API pages imported from AOO wiki to TDF wiki

[Ilmari Lauhakangas]

I did the import and initial cleanups today:
https://wiki.documentfoundation.org/API
https://wiki.documentfoundation.org/Category:API
Pages in AOO wiki:
https://wiki.openoffice.org/wiki/Category:API

I hope someone else can pick up the work and bring in missing files and 
things (or make decisions on what to point to instead), create new 
screenshots to replace the old ones etc.

Ilmari