Renamed and pre-selected Pivotal keybindings
Added style tweaks for indentation and spacing
Remove trailing spaces and ensure new lines
General setting tweaks.

Hide tips on startup. Show memory usage. Reopen last project on start.
Don't confirm exit.
Disallow placement of caret after end of line
Show line numbers
Merge branch 'master' into settings_tweaks
Merge pull request #5 from pivotal/settings_tweaks

Settings tweaks