base: deny region creation exceeding size of a ds

The rm_session implementation expects that offset + size must be
part of one dataspace. Unfortunately the parameters are not checked
properly during an rm::attach.

During an detach memory behind the actual region can be unmapped by such
bogus region entries.

Issues #591
noux: calculate rm::attach parameters correctly

Previous commit denies the creation of regions larger then the dataspace.
Noux does it by setting the default size to the dataspace size without
subtracting the offset.

Fixes #591
Print pthread stub messages to Genode log console

With this patch, the 'not implemented' messages of the pthread function
stubs always get printed to the Genode log console instead of stdout.

Issue #815.
bash: don't call 'check_dev_tty()'

The 'check_dev_tty()' function calls 'ttyname()', which calls the pthread
stub function 'pthread_main_np()', which prints a 'not implemented'
message. Calling 'check_dev_tty()' doesn't seem to be necessary, so this
patch removes the call.

Fixes #815.