INI Improvements and Threading

Incremented version to 1.6.1

Added never_run_ftl ini setting (Issue #17)
Added highlightall ini-setting removal and a deprecation comment to the ini header.

Added a lib folder to contain support modules.
LogicObj became LogicThread.
Made the patching thread killable.
Added cleanup handler for ctrl-c and Windows terminal closing.

Fixed data.dat/FTL.app file chooser, which sometimes left files hidden.

When the ini's ftl_dats_path is invalid, it will be ignored, so the user will be prompted again.
FTL is launched via subprocess.Popen() instead of os.system().

There's commented-out code to handle terminal closing on a non-Windows OS, but I'm reluctant to use it until it's confirmed that Linux and OSX universally signal as expected.