cscope: don't export trailing punctuation as part of symbol name

i.e. export include? as include so that cscope doesn't barf
add to changelog
cscope: only export all-non-word keys if they are definitions

cscope seems ok with the definition of a function "!" but not calls to it (and
especially not multiple consecutive calls like !!@var)
Merge pull request #50 from eapache/cscope-trailing-punc

Cscope trailing punc