Same as in r431, but now for lib/
- converted the sources in lib/ to use full path includes instead of just the filename.
- marked places where lib/ivis_*implementation* (eg opengl) is needed, because of incomplete lib/ivis_common.
Should improve the understanding of interfaces and code organization.
(Also fixed a double slash (//) include in src/multimenu.c)
git-svn-id: svn+ssh://svn.gna.org/svn/warzone/trunk@432 4a71c877-e1ca-e34f-864e-861f7616d084