Gap.app release candidate

This release candidate version is intended for GAP experts to help find (and fix) bugs. Sourceforge will be updated with a final version within the next few weeks. The source code is in git. This edition does not include a copy of GAP, which you'll need to have installed elsewhere.

New features in v0.5 (incl. the prerelease):

• Gap.app now works with versions of GAP after 4r4 -- tested with 4r5 and 4r8. (Worked around bug in command-line parsing where GAP has trouble with empty arguments)
• Command completion now works in error loop. (Worked around GAP bug where GAP doesn't escape @ correctly in error loops.)
• Command completion keeps the cursor visible.
• Command completion more correctly handles record variables.
• Better handling of errors on startup.
• Added Help preference pane, which allows selecting a help viewer.
• GAP output of carriage returns now clears to the beginning of the line.
• GAP output of backspace correctly deletes a character.
• More accurate calculation of screen width.
• Keyboard selection support is better.
• Limited support for ANSI/VT100 color codes (standard foreground colors only). Note that ColorPrompt is overridden by Gap.app choices of fonts.
• Ctrl-D to exit GAP is supported.
• Ctrl-C for interrupt is supported.
• A menu option under the GAP menu allows opening GAP in Terminal.app, or GAP Library Folder in Finder.
• Somewhat improved speed of output (e.g. of processing output from the Print function in GAP).
• Additional GAP options supported in preferences
• Gap.app will now save and open sessions. (A session consists of the GAP workspace, all GAP output, and all associated windows, for example from subgroup lattices.)
• Memory Usage inspector allows viewing Gasman statistics.
• Change font size for command window.
• Zoom into/out of command windows and xgap sheets.
• Added icon for .gapsession documents
• Redesigned application icon, added high resolution versions