This patch allows multiple marks to be set on a single window. The restriction that a mark may
only be on one window at a time is still upheld as this is necessary for commands like
"move window to mark" to make sense.
relates to #2014
If the match expression is a plain number (e.g., '99'), the number of a workspace will be compared strictly. Otherwise, the match expression is taken as a regular expression and compared against the workspace's name.
This allows all of the following:
for_window [workspace=5] ...
for_window [workspace="5:foo"] ...
for_window [workspace="foo"] ...
fixes#1769
eval 'package foo; use strict;' enables strict within eval, it does
not leak into the surrounding scope.
Also fix various warnings/compile errors found due to now enabled
strict and warnings.