Explicitly map text object inner and outer motions

No point in special casing just the text objects when every other
mapping is explicit
Change Meta- mappings for wrap element

Old mappings were awkward, and mapping <M-[> is a bad idea
Update comments
Refactor terminals_with_whitespace
Replace v:count with b:sexp_count in <Plug> mappings

This is kind of gross, but necessary so we can fall back on using
v:count in the absence of vim-repeat.
++todo
Beginning of doc/vim-sexp.txt
Remove multibyte search() bug handling

This is fixed upstream (by a handsome fellow), with 7.3.779, so there
is no need to keep our old code around, especially since it was an
extremely rare edge case to begin with.
++todo
Don't call searchpos() without 'n' flag

Complecting moving with searching is a headache. One cursor() call isn't
going to kill performance.
Don't delete delimiters with inner motions when contents are empty
Special handling for operator pending next bracket

This feels DWIM
Fix some equality checks

In particular, we shouldn't compare positions together directly, in case
the buffer or offset variables differ.

Also, only numbers should be compared with == ; strings will always be
qualified as ==# or ==?
s/backwards/backward/g
Re-add funky double substring slicing

Unconventional techniques should be annotated for future preservation.
Clarifying comment
Don't use the word "metacharacter"
Fix stackop_emit cursor position

This time it's correct
Fix comment
Alter ASCII banner