Followup to mantis 3009; missed the Lead Sight gauge in the 1st fix

Rechecked all other gauges that set slew=true in their contructors
(vs 1st pass which checked gauges that set slew=true in hudparse.cpp)
I think I got them all now...

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10476 387891d4-d844-0410-90c0-e4c51a9137d3
Add a scripting hook variable that specifies the mouse buttons. This variable is named MouseButton and is a bit field which uses the MOUSE_* defines (index 0 for right, 1 for left, 2 for middle).

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10477 387891d4-d844-0410-90c0-e4c51a9137d3
going through old revisions, r8540 is wrong, since it was like that in trunk -- memsetting the whole struct to -1 sets all integers and floats to -1 (so let's go back to the old way in case some old retail code relied on model_instance_num, model_num, or submodel_num being set to -1)

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10481 387891d4-d844-0410-90c0-e4c51a9137d3
From Axem: add hud-set-custom-gauge-active and hud-set-retail-gauge active

Deprecates hud-set-active-gauge and hud-activate-gauge-type in favor of hud-set-custom-gauge-active and hud-set-retail-gauge active, which are clearer to understand and now accept INT_MAX number of gauges, instead of just 1.

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10489 387891d4-d844-0410-90c0-e4c51a9137d3
the #define already has a (char)

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10491 387891d4-d844-0410-90c0-e4c51a9137d3
New method of handling quotes and comments that examines lines character by character like most languages do, instead of just searching for the start of a comment. If a comment character is inside a quoted string, it will not kick off a new comment. (This actually fixes the core design flaw that caused semicolons to truncate messages, so the $semicolon tag is technically no longer necessary. It will still be kept, of course.) Fixes Mantis #3001.

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10492 387891d4-d844-0410-90c0-e4c51a9137d3
Fix mantis 3019: flush bitmap to prevent alpha-additive-blend shenanigans with lua drawRectangle

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10493 387891d4-d844-0410-90c0-e4c51a9137d3