Refactoring: redirected a number of internal exports from schematool to actual implementation.
schematool_admin: schema keys now with microsecond resolution rather than datetime (to speed up testing).
Started dev of various migration tests.
schematool_admin: added support for uninstall, delete of candidate schema, and a safety catch for deletes.
schematool: added support for schema merge, works but incomplete
schematool_table: docs fixup
schematool_admin: fixup, used wrong 'not found' constant
schematool_transform: bugfix, oops
schematool_admin: docs fixup
simple_tests: masses of tests added, mostly not run yet
Makefile: added test-dev rule to start proper erlang env