Natural whitespace handling for SBT configuration parser AKA 'no more blankies'
Comments fixed #1574
Extract method - for new implementation. Not completed yet.
Corrections for "session save"
Handle xml content in session save
Cut valid text corrected
findMissingText now searchs recursive
Change additional constructor to what it should probably be

I am at a total loss for why this is not compiling.
Remove binary compatibility breakages and migrate new parser features into an internal package.
Acceptance tests for  and new .sbt parser.
Adding scaladoc commnets for SessionSettings, and fixing type in check file.
 #1628
Moved tests to internal package
Fixed #1630. Remove last line if last statement is being removed
Split to small methods
Split to small methods
 Comments #1630
@deprecated("Removed from the public API", "2.11.0") def isDefined: Boolean
Documentation and renaming of "blankies" into somethign a bit easier to find.

* Rename SPlitExpression* to `SbtParser` denoting that is parses .sbt files
* Adds a few todos
* Document APIs for internal usage.
.gitignore cleaned