Rename "bin" to "redi"

I used PyCharm to rename the bin/ directory to redi/, then updated some
additional references to bin, such as in Makefile and docs/conf.py.

This is a backwards-incompatiable change, so we should increment the
major version of the software.
Remove file accidentally committed.
Merge pull request #111 from ufl-taeber/bin-rename

Rename "bin" to "redi"