Survex To-Do List

Bugs

This gives "*** Singular!!!" warning with DEBUG_INVALID on:
```
1 2 50000 0 -
1 2 5 0 -30
```
aven: loading a .3d file with no survey data (or which has a valid header but is broken later) with a survey already loaded doesn't work well.
img.c: eliminate duplicate img_LABELs when reading .PLT files.
multiple readings:
average bearings specially - they don't average like normal numbers
%age gradients should probably average the same as angle gradients
Document - works like so:
```
*set open {
*set close }
*calibrate compass {000.5 001.0 001.25}
1 2 10.23 {000 001} -02
2 3 {10.16 10.17} 127 {+06 +05}
3 4 11.98 007 {+03 +03}
```
Implement as extension to number format so any suitable numeric value to be repeated?

check on monochrome, 16, and 256 colour displays - especially that depth colouring looks OK
Feed back redraw time to key based movement as in caverot? Or perhaps best not to? It depends on whether we expect people to hold down keys or not... Perhaps something smart where the first press is a fixed size, then after that it depends on the redraw?
dot (or some mark) for a fixed point not otherwise used
Z/X a bit "exponential"
tilt speed and direction on keys?
print subsurvey scales to whole plot???
grid: If you zoom in a long way, the grid display goes completely bonkers. I refer you to http://www.srcf.ucam.org/~dl267/snapshot1.png for an example.

aven: Finish adding calls to msg() so messages can be translated.
aven: Implement "print clipped to what's in the window".
aven: the preview window should display all the pages in one window, arranged in an n x m grid. We should be able to do this by subclassing wxPreviewFrame and overriding CreateCanvas. And CreateControlBar too perhaps, though we could just make the page nav buttons scroll the window to show that page.
aven: Once the above is done, the user should be able to enable/disable pages by clicking on them like in Toporobot (or on checkboxes next to them which I think is what Compass does?) It would also be nice to be able to drag the survey around relative to the pages so that page breaks can be moved to the least awkward positions...
Check skip blank pages works (checked printps)...
On Windows, if the default printer is on another machine which isn't switched on, there's a 5 second delay when bringing up the page setup dialog, during which aven is unresponsive. Some other applications exhibit similar 5 second delays, so we're not alone.

Platform specific versions of docs?
Put more terms in terminology in docs ? trip, instrument, ...
Finish off manual loose ends.
Look at using docbook2man instead of docbook-to-man (command is nsgmls man_aven.sgml | sgmlspl /usr/lib/perl5/sgmlspl-specs/docbook2man-spec.pl). Issues are: double space between sentences is lost; double blank lines appear in output; \ isn't understood.
Make sure there's documentation for all the various settings in print.ini (colours aren't documented at present)

flag legs as "skeletal" or something? (i.e. not in the cave passage) - e.g. a radiolocation leg from one passage to another isn't surface, but it isn't in the cave itself either (it's through rock). You could just call it surface but maybe later we want to use the surface flag to produce points for a surface triangulation...
?outlaw prefixes on stations in data legs (as Todd has lobbied for) and then the prefix of a leg == prefix of each end...?
comma separated dates in *date?
Find a solution to Thilo's "." problem.
Units in *fix (currently metres)

quotes in messages - translate too? e.g. `XXX' to « XXX ». Eric suggests not in French.
extract --help messages for translation.
control of output units in .err file and in stats at end of cavern run? In fact anywhere we report a value in degrees or metres, the units should be selectable

resolve FIXMEs in code
Default variance for topofil counter? (currently same as that of tape)
Rather than forming a linked list of components, solve each as it is identified? Beware of issues like those that revcomplist test checks.
Don't split other traverses at articulating traverses when reporting error stats.
flag nosurvey legs in .3d file
sort out title which goes in .3d file for this (if no *includes in ... it gets the title of the leafname of this .svx file, otherwise it's the leafnames of the *include-d files, comma-separated):
```
*begin mycave
*title "My Cave"
...
*end mycave
```
make img more modular (convert to C++?)
add support for .KST? Gary says documentation is out of date, and recent releases of winkarst have broken .KST export/import...
resolve documentation/examples mismatch for station based .XYZ files and implement reading of legs from them.

diffpos: compare connectivity (i.e legs as well as stations) - e.g.

foo.1 moved by (0.02, 0.10, -0.06)
leg between foo.1 and bar.2 removed
...
bar.2 moved by (-0.02, -0.05, 0.03)

improve .plt export to include less crude survey structure.
look at solution by QR factorisation in matrix.c more
consider disabling the more expensive asserts - turning them all off speeds up cavern by about 10%.