add FIXMEs for full grammar parsing

@tserong will probably have to fix these if he wants to incorporate this
class hierarchy into Hawk ;-) But of course we'd first need to split it
off into a separate gem (which should be easy - I've deliberately kept
the code fairly cleanly separated).
move #crm_configure_command to Pacemaker::CIBObject
rename #crm_configure_command to #configure_command

Done for consistency with #reconfigure_command and #delete_command, and
also bearing in mind that in future it's conceivable that the
configuration command might not always use crm, or might use other
commands in conjunction with crm (c.f. #reconfigure_command).
avoid hardcoding usage of class under test

Hardcoding makes it more difficult to refactor common test code
for reuse later on.
extend Pacemaker::Constraint::Colocation tests
implement Pacemaker::Constraint::Location
remove unused variable
implement location LWRP using library code
Merge pull request #48 from aspiers/location

add LWRP for location constraint