Optimize character case changing operations

Previously, performing e.g. visual '~' on a large file would completely
lock up the IDE. The culprit seemed to be the calls to replaceText() one
character at a time, which is not a cheap operation since each
replaceText() will for example trigger a DocumentChanged event.
DONT PUSH - disable some annoying logging
Add some aw, iw tests.
DONT PUSH: separate run-tests target in build.xml