Standard C imposes that names prefixed by `_` and types suffixed by `_t`
are reserved).  Hence:

- Public symbols and macros are prefixed by `tao_` and `TAO_`.

- Private/helper symbols and macros are prefixed by `tao__` and `TAO__`.

- Types are no longer suffixed by `_t`.

- `struct`/`enum`/`union` have the same name as their `typedef`
  counterpart.

- Headers define a macro `TAO_..._H_` to avoid being included more than
  once.

This results in an enormous number of changes but it makes the code more
consistent and, hopefully, easier to read/understand.  The code statements
have been mostly left untouched, the libraries compile and all tests that
do not require access to a device were successful.

Functions tao_parse_int and tao_parse_long takes an additional argument
to specify the basis for conversion and check for integer overflows.

Code for tao_parse_int, tao_parse_long and tao_parse_double has been moved
from cmdline.c to utils.c.

rate -> framerate
exposure -> exposuretime
fullwidth -> sensorwidth
fullheight -> sensorheight
pixel_type -> pixeltype
last_frame -> lastframe

The members of the ROI have `long` type (was `int`) to be consistent with
the conventions in TAO software.  This trigger a number of changes.