Remove the limitation on the number of dead keys
that we match, and allow the result be be multiple
characters.
Regenerate the builtin sequences, since this changes
what dead key sequences we can reproduce algorithmically.
Update tests to match.
Fixes: #10
All tables use the compact format now, and we generate
caches in that format too. Bump the cache version to 3
for this.
Replace the python script for generating the builtin table
by a small C program using the same code to generate the data
for the builtin table. This drops the restriction on only
generating a single character in the builtin sequences.
