Optimized t_opendir icons.

This also got rid of messages going "Warning: iCCP: known incorrect sRGB
profile" in the console as these PNGs were loaded.
Added "auto entry replace" option

This corresponds to forum request:
http://mancubus.net/forums/index.php/topic,1143.0.html
Remove test print.
Merge branch 'master' of https://github.com/sirjuddington/SLADE
Option not to save maps to disk directly

Mostly because I don't always want to actually save the random map
changes I make to test editor functions.
Consistency tweak
Fixed: Saving text didn't always work

Notably, it didn't work when saving non-text entries that were viewed as
text; in particular map labels when using "edit level script".
We don't actually need that bit.
Properly deal with "optional" keyword in jump to

Also added Blue Shadow's CVARINFO language definition.
Merge pull request #85 from Gaerzi/master

Sync with my fork.