Merge branch 'master' into jed/ts-eimex

Sync to include Git conversion, PETSC_EXTERN, and minor API changes.

Conflicts:
src/ts/interface/tsregall.c

Commit after merge.

Hg-commit: 529608adef0edbad5c2a5f57f3beefa5703bfae9

moved ao over to vec/is location
fixed couple mistakes in examples made by privitizing petscimpl.h

Hg-commit: 01295422394106db7c66f43df1606e60d84f7325