View Filters page HTML/CSS fixes
Project filter display [] around  'current'

For consistency with other meta filters like [any], [myself], we now
display '[current]' instead of 'current'
Project filters: fix preselection of current filter

The strict type checking for check_selected must be disabled when
dealing with projects/subprojects selection lists display. The
alternative (strict checks + type casts) prevents the current filter
from being preselected when editing it.
Fix type issues with check_selected in view_filter_page.php
Fix strict type issues (check_selected) in filters

Use of strict type checking for check_selected() must be disabled when
dealing with projects/subprojects selection lists display. The
alternative (strict checks + type casts) prevents the current filter
from being preselected when editing it, and also causes occasional
errors when displaying the filters.

Also includes HTML/CSS fixes.

Pull request #132