Fix incorrect search page count
Ignore invalid walls in some old saves, so that they load correctly

E.g. save 10631 from old server
revert b17ef7f93880 (couldn't figure out better fix for the new PSTN bug), fix annoyance with clicking on save comments changing pages
fix not being able to select / see all elements in menus with tons of elements
fix bottom row of saves in the save browser being cut off
SConscript changes from Doxin - option for scons to copy environment variables CC, CXX, LD, CFLAGS
Minute performance improvement for Sign.getText
Spark sign tool, {b|sometext}, when the sign is clicked, the a spark will be created at the signs position. Also MouseDown events that draw particles from being triggered when clicking on a sign
Do not allow 't/c' signs to lack an ID
fix Sconscript
Remove old unfinished virtual machine and Lua bindings for it
reduce / prevent PROT in fusion even more
Merge branch 'develop' of https://github.com/simtr/The-Powder-Toy into develop
fix issue with FILT PHOT scattering
fix copy and paste in the same tpt window on SDL/Linux/X11
Merge pull request #178 from mniip/x11-clipboard

fix copy and paste in the same tpt window on SDL/Linux/X11
fix crosscompiling, --lua-dir was being ignored
--copy_env copies LIBPATH (test to fix windows crosscompile)
Reject {b:1|blah} signs
Only cancel click events clickable signs (not all signs)