Setting version to 0.4.0-SNAPSHOT
Merge branch 'master' into release/v0.4.0

Conflicts:
	version.sbt
* Great refactoring! Made everything more `File`-centric;
* Abstracted parsing over particular language;
* Merged `literateFile/Dir` into one `File.literate()` method;
* Changed namespace;
Added the most useful languages
Changed language definition; Fixed handling of comments in strings
Merge branch 'feature/language-agnostic' into release/v0.4.0
Solved problem of nested comments; refactored parsers
Merge branch 'bugfix/nested-comments' into release/v0.4.0
Added autogenerated links definition list; changed index building
Merge branch 'feature/links-def-list' into release/v0.4.0
Separated parts into sbt-subprojects
Wrote simple sbt plugin
* plugin:
  + added `docsMap` key, for multiple mapping between srcs -> doc dirs;
  + added `docsOutputDirs` for adding them to `cleanFiles`;
* wrote a proper readme;
Merge branch 'feature/restructure/lib-plugin-app' into release/v0.4.0
Added thankme button
Moved thankme button to the bottom
Added release notes for 0.4.0; minor pre-release changes
Fixed docs auto-generation for subprojects
Improved docs a bit
Merge branch 'release/v0.4.0'