<rdar://problem/11109316>

command script import now does reloads - for real
If you invoke command script import foo and it detects that foo has already been imported, it will
 - invoke reload(foo) to reload the module in Python
 - re-invoke foo.__lldb_init_module
 This second step is necessary to ensure that LLDB does not keep cached copies of any formatter, command, ... that the module is providing

Usual caveats with Python imports persist. Among these:
 - if you have objects lurking around, reloading the module won't magically update them to reflect changes
 - if module A imports module B, reloading A won't reload B
These are Python-specific issues independent of LLDB that would require more extensive design work

The --allow-reload (-r) option is maintained for compatibility with existing scripts, but is clearly documented as redundant - reloading is always enabled whether you use it or not

llvm-svn: 182977