added basic infrastructure for meta information about deployed Rascal
code to be stored in META-INF/RASCAL.MF
added RASCAL.MF meta information for the Rascal project itself, such
that we can edit the Rascal files in the location where they are. The
trick is to define the Source configuration option in the RASCAL.MF file
to point to the root of the library and the root of the tutor source
code.

Also fixed dangling inputstreams that needed to be closed.
fixed minor issues with Rascal manifests
defaults for main and module are now 'null' in order to react properly
to non-configured options
added reusable function that aptly closes an opened inputstream when
checking for existence.
fixed unused imports
fixed npe
removed double implementation of toString() function. It is now defined
as toString(value v) = "<v>";

Note: there appear to be more toString functions with no evident purpose
in
Set,
List etc.
fixed complex bug in keyword parameter handling. The arguments in side
the scope of a function would get the static type of the value on the
call side rather than the static type of the formal parameter

added commandline handling based on keyword parameters, parameters
become names of options, types are used to parse the options.
removed old interface that used Result<IValue> to pass actual keyword
parameters
re-ordered the call interface back into the right order by refactoring
method signatures
(previously temporarily
switched some parameters to avoid problems with erasure and overloading
while
fixing
the type of kwparams)
fixed bug in Manifest loader
removed some commented out code
small fixes
streamlining help messages of cli
off by one
Merge branch 'master' of github.com:cwi-swat/rascal