Merge pull request #71 from darkstar21/develop

Separates modify tree tests into separate files and adds some unit tests for addNode
adds editable text selectability, restricts to literal nodes
changes color scheme
Merge pull request #72 from TessMyers/develop

changes color scheme
(test) tests adding a literal to a capture group
(test) tests adding literals inside of quantifieds
(test) tests adding nodes to charsets
(refactor) changed tree names in addNode tests