User defined locals in manhole shell

[nirs]

Typically, when you add a manhole to existing application, the application was not designed for this, so finding stuff from the manhole shell is hard or even impossible.

This patch adds a new locals optional argument, allowing a user to add application specific objects to manhole shell locals.

Example usage:

manhole.install(locals={'server', my_server})

From the manhole shell, you can now use "server":

>>> server.status()

Installed locals are not inherited by child processes, since they may be invalid in the child process.

Issue: #16

[coveralls]

Coverage increased (+0.14%) when pulling d7b70cb1227b1dbc5e0d1802fe52a1787487598b on nirs:locals into a3b9e84077d7410b5f4eb467d4ef6f0ac0ffdc90 on ionelmc:master.

[ionelmc]

Looks good. Just a quick question wrt inheriting the locals on reinstall, what if people put utilities (like a get_memory_stats) in the locals? They would want those to be inherited.

[nirs]

Ok, looks like it is the user responsibility. If you are enable automatic installation in child process, you are responsible to use the locals correctly.

I'll post another version, this should make the code much simpler.

[nirs]

I posted a new version that support locals inheritance #18.