Don't run 'exec_action' blindly.
Add support for 'parameter' where appropriate.
Only return cleaned-up module names.

- strip module descriptions
- strip indentation from list output
- strip internal modules (help, usage, version)
Strip additional output from targets, return only actual targets.
Added 'parameter' to CLI examples.
Deprecate 'parameter' in favour of 'module_parameter'/'action_parameter'.

A generic 'parameter' argument doesn't cover what's actually required.
In some cases, parameters need to be passed either to the executed
module, action or both.

This changes gracefully deprecate the old 'parameter'.
Handle 'target' + 'action_parameter' in 'set_target()' correctly.
Documentation improvements for get_modules() and get_target_list().
Be a bit more careful with the results of 'exec_action()' and also sanitize them a bit.

In case the 'exec_action()' call for 'get_target_list()' returned no
results, because there were no available targets, the module would
stacktrace.
Documentation improvements for 'get_current_target()'.
Handle '(unset)' as return value (when no target is set) in get_current_target().
Documentation improvements for 'set_target()'.
Documentation improvements for 'exec_action()'.
Don't try to run blindly non-existent modules.
Documentation improvements for 'set_()'.
No exceptions in execution modules.
Pylint.
Add missing import of 'salt.utils'.
Pylint.
Merge pull request #18814 from eliasp/2014.7-eselect-improvements

2014.7 eselect improvements