Put all extended doc strings into separate txt files

Move all extended doc strings from thalia.doc strings to separate text
files with names of the form:

    doc/project-docs/<lang>/<project-name>/<version>/<namespace>/<symbol>.txt

This makes it easier to edit the extended doc strings of different
symbols independently of each other.

Add create-doc-rsrc command to make a single file resource/<lang>.clj
file from txt files, so that in the release, a single resource file is
enough to read in for all extended doc strings for one language.

Also start moving towards a 0.1.0 release.

None of this is tested on Windows yet, only Mac OS X, although Linux
is close enough that it should have no problems.