Replaced hook-calling for multiple functions by proper `define-hook` versions
Merge branch 'master' of github.com:cram-code/cram_core
Reintroduce designator logging upon using `with-designators`
Fixed the logging hooks for cram_reasoning to use `define-hook'
Merge branch 'master' of github.com:cram-code/cram_core
Added capabilities for storing temporary variables during run of policies
Reconsidered handling of lexical scopes in policy execution

When defining variables in different phases of a policy and storing them using `policy-setf' and `policy-get', their lexical scope is now handled properly and they are available at all times.
Changed the semantics of the `on-fail' hook from `condition' to `datum'.

Up to now, the `on-fail' hook (executed when a failure is happening) transported the `condition' value of the failure, which is less information than the actual `datum' variable that becomes available when the error comes up. The `datum' variable includes not only the failure name and class, but also the package it is originating from. For the sake of completeness, this is now used as the parameter for `on-fail'. After double-checking neighbouring code in the CRAM stacks, nothing besides `cram_beliefstate' actually uses this callback hook.
Added optional 'or' concatenation of failure cases when using 'with-failure-handing'
Changed symbol checks for 'or' from string= to direct eql symbol comparison
Merge branch 'master' of github.com:cram-code/cram_core
''with-policy'' and ''with-failure-handling'' are now equipped with hooks
[reasoning] added a MAX predicate + some missing symbol exports.
Merge pull request #18 from fairlight1337/master

Hooks for beliefstate logging + new feature for WITH-FAILURE-HANDLING.
[language] improved version of WITH-FAILURE-HANDLING
Merge pull request #20 from gaya-/reasoning_stuff_branch

MAX Prolog predicate