more intelligent about ignoring files that are clearly not modules

something to show

function

added display of deprecated to ansible-doc
now it does better job of using tty columns
fixed indication truncation of desc with trailing ...
removed extension from module list, also fixed matching exlusion
blacklist

documenting them. Soon will be patched to recognize them as either
deprecated or an alias

'_', they will be loaded after non prefixed modules are checked they can
be full modules or symlinks to existing ones (alias)

also updated ansible doc to ignore these, will eventually add selective
display

* added ability to set parents (will be used when the deps are loaded)
* added role caching, so roles are not reloaded needlessly (and for
  use in detecting when roles have already been run)
* reworked the way metadata was stored - now individual attribute fields
  instead of a dictionary blob

Update playbooks_roles.rst

Typo fix in playbooks_intro.rst

Ignore compiled Python for documentation.

Update developing_modules.rst

Fix the synopsis in ansible-pull man page.

Small punctuation/grammar fix.

When running `ansible-doc --list` a lot of errors are
generated when `ansible-doc` tries to find documentation
strings in `.pyc` files.

Fixes #9316

Fixes #9399

This reverts commit a6029264.

Fixes #9400

Update intro_installation.rst