Improve tab-completion for emacs in terminals

- Final commits for 0.8.0 tag. - Missing part of win32 install patch by N. Pernetty that I'd inadvertedly not applied. - Unicode fixes for emacs under win32 - Small bug fix (recently introduced) in pycolorize. - Improve handling of history file after %run, reduces memory usage.

Install signal handler on each code run to protect against user code that may modify it as well. If we don't do this, on the next Ctrl-C python itself will likely just crash completely.

- Various small fixes and cleanups. - Proper determination of main thread id, thanks to Stefan.

- Mark Release Candidate 1 for version 0.7.4.

- I possibly cross-thread KeyboardInterrupt support for the multithreaded shells. This is still pretty hackish, so testing is needed.

Further reduce the number of cases where autocall may be unnecessarily activated.

added ipy_completers.py, ipy_stock_completers.py now only ENABLES the completers as opposed to implementing them

- Close #131.

Prevent %debug from not working if pydb 1.17 is installed, which has a fatal bug