Fixed to small memory leaks
Generate error message in case bibtex generation fails

In case bibtex fails no message is given. When perl is missing the OS just emits an message. With this patch doxygen logs a message (analogous to other calls to portable_system)
Empty entry in \tableofcontents in case e.g. section without description.

In case a section, subsection etc just has a tag and not a description in the \tableofcontents there is nothing mentioned. With this patch the tag is used as description when no description is present, as is done on other places as well (consistency and no empty items in the \tableofcontents).
Bug 738063 - Fortran attribute contiguous not identified

Added keywords contiguous and volatile
Bug 737444 - Java: Annotations with brackets prevent documentation
Merge pull request #233 from albert-github/feature/bug_cite_perl

Generate error message in case bibtex generation fails
Merge pull request #234 from albert-github/feature/bug_toc

Empty entry in \tableofcontents in case e.g. section without description
Merge pull request #235 from albert-github/feature/bug_738063

Bug 738063 - Fortran attribute contiguous not identified