Revise computation of labels

Instead of relying on random numbers, we use a hash of the objects's name,
plus a label counter (which helps to avoid giving things with the same name
the same label).

As hash function we use CRC32, which has the advantage of already being
provided by GAP (and this is what GAPDoc uses, too). Drawback: This is
not a very good hash and collisions are possible. But for our purposes
it should be fine.
Updated author info gutsche.
Merge branch 'label_hash' of github.com:fingolfin/AutoDoc

* 'label_hash' of github.com:fingolfin/AutoDoc:
  Revise computation of labels
Rearranged files.
FIxed doc parts.
New file structure again.
Add newlines after generated <#Include> statements
CreateTitlePage: Directly output version into title.xml

Previously, we instead inserted an <#Include> for the ../VERSION
file. But not every package will have such a file.
Add newlines at end of file
Shorten AUTODOC_XML_HEADER, remove trailing whitespace in it
Improve Create{Main,Title}Page
CreateTitlePage: Introduce OutWithTag() to improve output

Readability (= "nice looks") of the generated XML seems important for
marketing reasons if we want to encourage use of AutoDoc for creating
documentation.
CreateTitlePage: also show maintainers

Perhaps this should be configurable, or perhaps maintainers should be
marked as such, but they definitely should be mentioned.
Create{Title,Main}Page: Some TODO comments
misc: reduce some minor code duplication
Moved Install doc entries to AutoDocEntries.g
Moved Create doc entries to new file.
Moved main doc file to new file.
Modified CreateAutoDoc for AutoDoc itself.
Enabled AutoDoc for AutoDoc.