ACME-1236 : WIP : Added the vignette mode. Can be applied to colorCorrect and color Transform. Added new -v argument to llimage_libtest

ACME-1236 : WIP : added all the color correction filters: colorize, linarize, equalize, contrast, brightness

ACME-1236 : WIP : add filterGamma, computeHistograms, colorCorrect, implemented filter gamma to llimage_libtest for testing

ACME-1236 : WIP : add filterRotate to rotate hue, add rotate as a valid argument to --filter in llimage_libtest

ACME-1236 : WIP : Implement saturation/desaturation transform filter, add it to llimage_libtest for testing

ACME-1236 : WIP : Implement colorTransform filter, grayscale and sepia using it, add parameter to llimage_libtest to use filters

ACME-1043 : Fixed! Added an argument to force a clean full feature browser window in some situations

ACME-1043 : WIP : Add an argument to open trusted content with js and other enabled options, bypassing prefs

ACME-1117 : Fixed crash in Facebook checkin in logged out situation, check presence of region before accessing it

If a marker file indicates that an installer has been downloaded and verified
and is ready to install, but that installer file does not exist, log it and
revert to checking for update.
Also add logging to every code path that can remove the installer explicitly,
in case the missing installer is actually being killed off by some weird
sequence of state-machine transitions.

Also, delete it when done.