Never select tabstop with regex transforms

[bjin]

Fixes #66

[bjin]

I did some testing and found out that in combine with a placeholder like ${1:something}, this patch just mess up cursor position. Some indexing code might silently depends on a liner scan (from left to right) for same tabstop, I guess. I don't know much about the codebase. Some small digging just make things even more confusing.

Closing for now, as I couldn't come up with a proper fix.

[bjin]

Replace $1 with ${1:&n} to test how the code handles placeholders.

[dcampos]

I'll reopen and merge this, as I think I've found a fix for the placeholder bug.