Implementation of Tab spaces and indentation size.

[LCrawford13]

This addresses issue #668. Currently not finished, the GUI for the settings is finished. And both features work AFTER opening the program and altering the settings. The default settings won't work properly. Indent size works partially, that is, when tabbing the indent size will be correct, but it will be made up of a mixture of tabs and spaces, rather than one tab of the indent size.

Example 1, on startup with indent size of 10:

Example 2, after changing the settings such that indent size is 10:

For tab spaces, while writing this I discovered pull request #642, so I'm assuming that adding tab spaces is more complicated than it appears. Will indent size apply to languages too?