remove timout garbage collector

This is not a viable approach -- the initialize/finalize hooks create reference cycles which screw python garbage collection.  One could use weakrefs, but if we cannot guarantee that a connection which got timed out can be re-instantiated, then we should not mess with the connection in the first place.

However, this commit still does not solve the garbage collection problem -- while the adaptor destructors are now correctly called at the end of the program execution, I see no sign of any earlier garbage collection activities, no matter the runtime, obj usage etc.  So, this needs further debugging...
fix /bin/sh startup check on non-default sh prompt

... as for example needed on stampede :-P
improve error message for failing shell startup
merge from devel
Merge branch 'devel' into fixes
GC now works, connection restart does not.

So, I had to revise my notion of python's variable scope, and with that newly
gained insight (a nice word for brain damage in this case) supports the result
that shell garbage collection now works as expected.
fix and enable test for #74
working_directory creation, fixes #88
updated version and changelog
updated examples
fix for #91
removed resource list
fix CWD interpretation for shell adaptors

I am sure you will appreciate the diff :-)
make documentation more specific
pending changes
Merge branch 'devel' into feature/http
updated file adaptor tests and examples
rmeoved csh
Merge branch 'devel' of github.com:saga-project/saga-python into devel
added missing file