Merge pull request #3 from rfrank/develop

sync Develop
Better error messages for unclosed blocks at end-of-file

Updated doLit to check for unclosed .li (which was only partially checked,
before, during footnote handling in HTML).

Updated footnote handling in text to skip over .li blocks.

Updated doDef to detect unfinished .de (command continued at end-of-file).

Removed superfluous "i += 1" in a "for" block.
Merge branch 'develop' of https://github.com/wf49670/ppgen.git into develop
.na with .nf c
Merge branch 'develop' of https://github.com/rfrank/ppgen.git into develop
Merge pull request #35 from wf49670/develop

resync Develop from rfrank
Fix for one error and implementation of .nr Footnote and .nr Illustration
Merge pull request #36 from wf49670/develop

Fix for one error and implement .nr Footnote and .nr Illustration
check for missing .dv-
Bugfix for .nr Footnote and .nr Illustration
Merge pull request #37 from wf49670/develop

Pull from wf49670 Develop
version 3.37