Use bool for flags in oparg_T.

Several opart_T members like use_reg_one, end_adjusted, empty,
is_VIsual, and block_mode, only ever store TRUE or FALSE, so make this
constraint explicit by changing them to bools, and TRUE to true and
FALSE to false in the context of their uses.

The member, inclusive, has several other uses such as in arithmetic
equations and one inequality, but every single assignment (obtained with
'grep -r "inclusive \\="') sets it to either TRUE or FALSE.

This also implies that the inequality, "oap->end.coladd <
oap->inclusive", can only be true when coladd==0 and inclusive==true, so
test for that instead.

For consistency, change the first argument of findpar (which ends up
being inclusive) to bool.

Include stdbool.h for consistency with issue #918.

This commit shrinks the size of oparg_T from 128 bytes to 112 (-13%) on
my machine.
Use bool in normal_cmd().

Change signature of set_vcount_ca for consistency.
Use bool in do_mouse().

Change the signature of get_mouse_button() for consistency, and because
only do_mouse() uses it.
Use bool or int for local flag variables.

In do_pending_operator(), nv_zet(), nv_indent(), nv_g_cmd(), and more,
replace integer flags with bools when appropriate.

However, do keep the TRUEs and FALSEs of nv_cmds[].cmd_arg. It may store
values other than TRUE or FALSE, so it seems to make sense to use
integral constants.
Use bool in signatures of functions in normal.h.

Return bool from checkclearop, checkclearopq, add_to_showcmd,
find_decl, nv_screengo, get_visual_text, and unadjust_for_sel as these
functions all return either TRUE or FALSE or OK or FAIL, but not MAYBE.

Change to arguments toplevel of normal_cmd, check of
do_check_scrollbind, and locally and thisblock of finddecl, to bools as
they represent predicates.
normal.c: Replace last TRUE/FALSE/OK/FAIL's w/bool.
Fix fileio.c's diagram.
vim-patch:7.4.414

Problem:    Cannot define a command only when it's used.
Solution:   Add the CmdUndefined autocommand event. (partly by Yasuhiro
            Matsumoto)

https://code.google.com/p/vim/source/detail?r=v7-4-414
vim-patch:7.4.415

Problem:    Cannot build.  Warning for shadowed variable. (John Little)
Solution:   Add missing change.  Remove declaration.

https://code.google.com/p/vim/source/detail?name=v7-4-414&r=20dbceb6f4713ccd01be45dc531abc269fbb7579
Merge pull request #923 from splinterofchaos/normal-bool

Use bool in normal.h and .c.
Merge pull request #1282 from splinterofchaos/cmd-undef

vim-patch:7.4.414 + vim-patch:7.4.415
eval: Add eval_call_provider/eval_has_provider functions

These use autoloaded vimscript to replace the provider_call/provider_has
functions, moving the implementation of providers to pure vimscript(we lose
nothing since vimscript can also call msgpack-rpc functions).

When calling the rpcrequest function from a provider, temporarily switch to the
caller scope. This is required for compatibility with legacy plugins, because
they may depend on scope information that changes when "leaving" the C stack to
enter the vimscript stack.
eval/ex_cmds2/ops: Implement providers with eval_call_provider

Replace references to provider_call/provider_has with the new functions
eval_call_provider/eval_has_provider.
Remove os/provider.{c,h} and all of its references
runtime: implement python/clipboard with runtime scripts

- Move the python provider implementation(script_host.py) from the python-client
  repository to this one
- Use the autoload scripts to implement python/clipboard features
- Add runtime scripts for working with external plugins and hosts
- Add tests for the new runtime scripts