SystemTools: Do not abort with no current directory
SystemTools: Do not abort with no current directory

Remove the abort() from the internal Getcwd implementation.  All callers
check the return value already.  Fix one caller's "else" behavior to
avoid crashing.

Change-Id: I3450c4942ffa108b2313877c9472820f6b465baa

chuckatkins/KWSys,chuckatkins/KWSys,chuckatkins/KWSys,chuckatkins/KWSys