Move j,k to the new system.
Move w,b,e to the new system.
Add FAILHARD=1 environment variable to abort on the first test failure.
More cleanup between tests:
* Clear numarg
* Attempt to close any splits.
Add another test of '$', with prefix count.
Update cw test to better match vim behaviour - it's treated more like ce
(doesn't include the space following the word).
Update for cw not including space after the word.
Further changes towards the new motion system.
* Rename "debug" variable to "debugFlag" to avoid shadowing debug library.
* Update do_keys to recognise nested tables (key sequences)
* Move vi_cut to vi_ops.cut.
* Add a function to read/clear the prefix argument.
* Move c and d to use the new motion system.
* Move '$' into vi_motion.lua
* Change how counted motions are done - some can't be done just by repeating,
eg '$'.  Add a wrapper (r()), which turns a simple one into a repeated one
with passed-in rpt.
Tweak to cw_count so that it fails a bit later.