lib-dict: Compiler warning fix

lib-dict: Add support for lookup to return multiple values Implements only the initial stubs to the drivers.

lib-dict: Add dict_transaction_set_timestamp()

lib-dict: Added dict_iterate_set_limit()

lib-dict: Added dict_transaction_no_slowness_warning()

lib-dict: Added DICT_COMMIT_RET_WRITE_UNCERTAIN

lib-dict: Added enum dict_commit_ret.

lib-dict: Added dict_switch_ioloop()

lib-dict: dict_transaction_commit*() returns now error string

lib-dict: dict_iterate_deinit() returns now error string

lib-dict: Changed dict_wait() to return void. If it encounters any failures, it should just make sure to abort any pending async requests before returning.

lib-dict: dict_lookup() returns now error string

lib-dict: Renamed dict_init_full() to dict_init()

lib-dict: remove dict_append() Remove all *_dict_append and redis_append functions and corresponding command from lib-dict.

lib-dict: Added async API for lookup and iteration.

Removed all invocations of atoi().

lib-dict: Added DICT_ITERATE_FLAG_EXACT_KEY flag. This is mainly useful with SQL for iterating through a result that has multiple rows.

lib-dict: file backend now expands ~/ paths if home_dir setting is set.

lib-dict: Changed dict.init() API to take struct dict_settings and added dict_init_full(). This allows giving more settings to dict in future as needed. Unfortunately it also breaks the internal dict API, but there aren't really any plugins widely using it, so it's not a big problem.

lib-dict: Added DICT_ITERATE_FLAG_NO_VALUE This allows iterating dictionary without wasting extra time on returning values that aren't needed.

lib-dict: dict_init() now returns error string instead of logging it

dict_init() API changed to return int.

dict: Implemented dict_append()

Marked functions parameters that are allowed to be NULL. Some APIs were also changed. The non-obvious APIs where NULL parameter was changed to "" are master_service_init() and auth_master_user_list_init(). These checks can currently be enabled only on a patched clang: http://llvm.org/bugs/show_bug.cgi?id=6786

Fixing my english: s/non-?existing/nonexistent/

dict: Added dict_iterate_init_multiple(). --HG-- branch : HEAD

lib-dict: Changed dict_iterate API. --HG-- branch : HEAD

lib-dict: Added dict_[un]escape_string(). --HG-- branch : HEAD

dict: Added support for async commits. Changed dict_atomic_inc() behavior. --HG-- branch : HEAD

dict proxy: Use base_dir as the default dict-server location. --HG-- branch : HEAD

Added dict_transaction_commit_async(). --HG-- branch : HEAD

Added a simple flat file dict backend. --HG-- branch : HEAD

dict API: deinit functions now take pointer-to-pointer parameter which gets NULLed. --HG-- branch : HEAD

Changed .h ifdef/defines to use <NAME>_H format. --HG-- branch : HEAD

Berkeley DB dict support is now enabled only when using --with-db configure option. --HG-- branch : HEAD

Dictionary changes: Added support for defining value's type. Key is still always a string. Added support for sorting the iteration replies. Added dict_unset(). Added Berkeley DB support. Most of the code written by Tianyan Liu. --HG-- branch : HEAD

Dictionary takes now a username parameter, which is used for private queries. Made dict-sql use "insert .. on duplicate key update" syntax, which unfortunately doesn't work with PostgreSQL yet. --HG-- branch : HEAD

deinit, unref, destroy, close, free, etc. functions now take a pointer to their data pointer, and set it to NULL. This makes double-frees less likely to cause security holes. --HG-- branch : HEAD

Added "bool" type and changed all ints that were used as booleans to bool. --HG-- branch : HEAD

Added dictinary lookup server and a "proxy" dict implementation to talk to it. --HG-- branch : HEAD

API changes --HG-- branch : HEAD

Added dictionary API and implementation for SQL. It's meant for looking and modifying key=value pairs. In future we may need to use this for many different things, but for now it's only used by quota-dict plugin. --HG-- branch : HEAD