[Patch v3 1/6] lib: add "verbose" versions of notmuch_database_{open,create}

This has the the non-trivial side effect silencing all output to stderror from these two routines. The stdargs based infrastucture will be used in following commits for a more general logging mechanism. The changes to notmuch-{new,search} and test/symbol-test are just to make the test suite pass.

[Patch v3 1/6] lib: add "verbose" versions of notmuch_database_{open,create}

This has the the non-trivial side effect silencing all output to stderror from these two routines. The stdargs based infrastucture will be used in following commits for a more general logging mechanism. The changes to notmuch-{new,search} and test/symbol-test are just to make the test suite pass.