documentation: fewer categories
repaired bug in poly_db_count
Merge branch 'master' into update
Merge branch 'update' of https://github.com/solros/poly_db into update
* enabled restricted read access (by adding username and password options to read functions poly_db, poly_db_count, poly_db_one and their wrappers)

* removed functions poly_db_smooth_reflexive_vertices
moved db functions to application common
new DatabaseCursor object
Merge branch 'cursor'
changed insert and update function names so they don't begin with poly anymore
Merge branch 'master' into update
documentation for DatabaseCursor
removed bug in DatabaseCursor
changed poly_db functions to undef their client
minor changes to DatabaseCursor
documentation
Merge branch 'master' into update
updated README
Merge branch 'master' into update
typo
bug fixes in update_client