#2 Additional features for m_vstrlist

[Tim Cera]

Added several functions useful to me to m_vstringlist...

vstrlist_iterator: Return newstring in starting at element 1 and progressing through the list, each time vstrlist_iterator is called.
vstrlist_iterator_reset: Resets the vstrlist_iterator so that the next vstrlist_iterator will return the first element.

vstrlist_pop_last: Return the last element of the list, then delete it.
vstrlist_pop_first: Return the first element of the list, then delete it.

vstrlist_del: Delete an element from the list.

At this point I extensively use vstrlist_pop_first (and by extension vstrlist_del). Really needs to have tests, but a cursory glance I had trouble figuring out the test framework.

Kindest regards,
Tim

[Tim Cera]

Diff style patch file