Editor: Fix transposeCharacters command, add tests.
http://bugs.activestate.com/show_bug.cgi?id=73992
r=marky
rn=
Use emacs as a reference, including the (useful) inconsitency for behavior at end-of-line. At start of line, does what emacs does, moving the first char on the line to the end of the previous line.  Elsewhere swaps prev and current chars, and advances cursor (which is what emacs does...)

(integrated from komodo (trunk) change 83446 by ericp)

git-svn-id: http://svn.openkomodo.com/repos/openkomodo/trunk@14129 b87d16e7-d29f-4ee1-b5ec-817d645d335f