Use ensime root-dir to find the sbt project path
Save all buffers before compiling (and some other sbt actions)
Reset compilation errors before running an sbt command

Previously, old errors were mixed with new errors, which made
a mess of things.
Fix position of zero-length overlays.

The old behavior tended to highlight whitespace, and with the default
highlight face the location was invisible.
Fixed ensime-internalize-offset for DOS format
Fixed some issues with DOS-format files

* Use ensime-internalize-offset where appropriate
Fixed more offsets in DOS mode
Backported changes from the working package.
Merge branch 'fix-compile-save' of https://github.com/edani/ensime-src into edani-fix-compile-save

Conflicts:
	src/main/elisp/ensime-sbt.el
Merge branch 'fix-overlay' of https://github.com/edani/ensime-src into edani-fix-overlay
Merge pull request #9 from edani/fix-root-dir

Use ensime root-dir to find the sbt project path
Merge pull request #10 from edani/fix-sbt-compile

Reset compilation errors before running an sbt command
Merge pull request #11 from edani/fix-offsets

Fix offsets for DOS mode