[MP] Clamp scr_conspeed to be in the range 1-100

It was possible to set scr_conspeed to a negative value, which would cause
the console to expand when the user wanted to close it, instead of
shrinking (and then disappearing).
[SP] Clamp scr_conspeed to be in the range 1-100

It was possible to set scr_conspeed to a negative value, which would cause
the console to expand when the user wanted to close it, instead of
shrinking (and then disappearing).
[SP] Remove R_LoadDataImage
[MP] Fix potential buffer overflow in PS_ReadPrimitive

Found by Coverity.
[MP] Fix unchecked buffer size issues in l_script.cpp and l_precomp.cpp

Found by Coverity.
[MP] Fix potential buffer overflow caused by long tcMod surfaceSprites, and ss args

Found by Coverity.
[SP] Fix potential buffer overflow caused by long tcMod surfaceSprites, and ss args

Found by Coverity.
Fix OOB access in CM_EdgePlaneNum
Merge pull request #547 from BSzili/master

JK2SP menu fixes
[SP] Some fixes for issues in both SP games pointed out by Coverity.
[SP] Fix OOB access in CM_EdgePlaneNum
[SP] Fix UI_FeederItemText and SE_GetString with JK2 Mode having redundant code.