Change cpp from innermost to outermost

Closes #116.
Use nrepl load-file for :[range]Eval

Closes #83.
Merge branch master into guns
Accidental mutation
Slightly more elaborate hack to detect final nREPL response
Different gross hack for extracting backtrace

Now instead of wrapping the code up in a try/catch, we just use a series
of evals to grab *e and then restore *1/*2/*3.
Merge branch master into guns
Encapsulate user ns
Allow overriding buffer namespace
Merge branch master into guns
Fix :Connect with no arguments

Closes #120.
Fix :Connect with argument

References #120.
Fix debugging statement
Python all the way
So many missing aborts
Merge branch master into guns
Allow debugging connection failures
Generalize interface between Vim and Python
Restore accidentally deleted polling
Default to sending session id