Bug 715172 - Consistently document Fortran's equivalent function bodies

Although controversioal but for consistency converted type for fortran functions to lowercase
Bug 719639 - @xrefitem with empty heading string

Adjusted documentation and in case the title is the empty string in a DocXRefItem the visitPre and visitPost do nothing.
Some texts can be independent of \htmlonly / \latexonly
Bug 719639 - @xrefitem with empty heading string

Replaced:
  if (!(x->title().length())) return;
by:
  if (x->title().isEmpty()) return;
Bug 668424 - HTML links in RTF output are broken

There are different types of hyperlinks: external and internal. The internal hyperlinks should have \\l behind the word HYPERLINK, the external shouldnt.
Bug 719489 - Label "abstract" instead of "pure virtual" for Java language

Proposed patch so the word abstract is recorded correctly in case of Java
Bug 711378 - Nested Aliases fail when the nested alias has two or more arguments.
Merge pull request #64 from albert-github/feature/bug_719489

Bug 719489 - Label "abstract" instead of "pure virtual" for Java language
Merge branch 'master' of github.com:doxygen/doxygen
Merge pull request #63 from albert-github/feature/bug_668424

Bug 668424 - HTML links in RTF output are broken
Merge branch 'master' of github.com:doxygen/doxygen
Merge pull request #62 from albert-github/feature/bug_docu_index

Some texts can be independent of \htmlonly / \latexonly
Merge pull request #61 from albert-github/feature/bug_719639

Bug 719639 - @xrefitem with empty heading string
Merge branch 'master' of github.com:doxygen/doxygen
Merge pull request #59 from albert-github/feature/bug_715172

Bug 715172 - Consistently document Fortran's equivalent function bodies
Merge branch 'master' of github.com:doxygen/doxygen
Bug 720046 - Document inline objective-C blocks
Bug 719591 - expand_as_defined macro does not properly work
Bug 719463 - Invalid null key and segmentation fault
Bug 719422 - private java class is mentioned in inherited by list of super class