[FIX] remove handling of parameters in ormcache clearing

[FIX] remove handling of parameters in ormcache clearing

It's completely broken in case of optional parameters
e.g. (ir.translation)._get_source, as a call with the optional
parameter won't be matched by a clear without, and the other way
around. This becomes even more problematic in the website branch as
_get_source now has *two* optional parameters (source and res_id).

After discussion with odo and discovery that in multiprocess only the
current node will use any granularity (other nodes not only clear all
of the current method cache, but all caches of all models), simplify
cache clearing, ignore parameters and just blow the current method's
cache entirely.

bzr revid: xmo@openerp.com-20131024132956-4tl3prum8za47igy