Bugfix
schematool now emits the final schema as a file foo.schema.term, which is our preferred solution. (E.g., make rules work nicely.) Simplified code since we no longer need to generate two modules. Generated .erl and .beam still retained, but can easily be removed after running. Schema is now consulted from file (rather than loading and calling a module).
schematool_transform: use mnesia:transform_table. This version successfully migrated a simple layout change.
schematool_helper: stubbed entrypoints for node and table add/del
Added helper callthroughs, implemented delete/create table on node.
add_node/1, delete_node/1 now implemented (but not tested).
# This is a combination of 2 commits.
# The first commit's message is:

Added support for altering table type and runtime helpers for this. Here, we start to grapple with the fact that we can optimize how table copying is done, as well as merge other tasks (such as layout transform) into the same task. Looks like that will make migration planning more complex when applicable, but that the final result should be faster. We should still detect when copying is NOT needed, and handle those cases less expensively. Also, we should probably produce a correct-and-complete-but-maybe-slow version before starting in on the complex optimizations.

# This is the 2nd commit message:

Added test for whether table migration requires copying. This will be used to decide migration strategy.
Added support for altering table type and runtime helpers for
this. Here, we start to grapple with the fact that we can optimize how
table copying is done, as well as merge other tasks (such as layout
transform) into the same task.

Looks like that will make migration planning more complex when
applicable, but that the final result should be faster. We should
still detect when copying is NOT needed, and handle those cases less
expensively.

Added test for whether table migration requires copying. This will be
used to decide migration strategy.

We should produce a correct-and-complete-but-maybe-slow version before
starting in on the complex optimizations.

Schematool now ensures that all nodes are connected and have started
mnesia before creating the schema. Should be refactored to
also be invoked before all other schema updates.
schematool: Added mild version tracking when loading schemas; also made sure the various operations wait for mnesia to start before running. (The latter has occured when invoked from Makefiles.)
schematool_table: added comment entry on how many records need to be transformed (per table).
Start of support for fragmented tables.