Fix format of logs of dbus calls.
Compile to C99.

Addressing
warning: ISO C90 forbids mixed declarations and code
warning: ISO C90 forbids specifying subobject to initialize
Support +VARIABLE name to append (or set only when previously unset, when no separator and no Iter is used).
apr_hash_count can be used to get the number of keys instead of looping.
Update .spec for 0.9.0.
Minor README tweaks.