Line Change Detection Complete

The detection of program line changes should now be complete.  This feature is necessary so that program lines can be incrementally compiled as they are modified.  Even though the implementation was starting to look rather complicated, it turned out to be fairly simply, which was mostly concentrated in the processing of the edit box document's contents change signal that contained sufficient information to report line changes.  From the time the new implementation was started, the size of the edit box code was reduced by about half and the previous implementation wasn't complete.

The next step is to connect the new program changed signal from the edit box to some new program class that will eventually hold the BASIC program code, though the goal of the current 0.3.x release series is to get the translator part hooked up.  However, this is a good point to make a development release.  In preparation for this, there was some minor cleanup of the code:

1. Renamed the edit box line number widget related functions with the consistent prefix of lineNumberWidget (separate commit).
2. Corrected a memory leak of the edit box instance by assigning the main window as its parent.
3. Removed the setting of the ignore change flag at the end of the edit box key press event handler (this flag is now only used when a new program is set).
4. Updated the copyright of the modified files and a few other very minor changes.

The various files (CMake, read me, and release notes) were updated for this development release and the code was given the tag v0.3.2.

[commit a2cfa5361a] [commit a13c485632]