Add command line parsing

Here we introduce command line parsing with help output.

| usage: yoda.py [-h] -f FILE -n NAME [-d DIR]
|
| optional arguments:
|  -h, --help            show this help message and exit
|  -f FILE, --file FILE  yoda file to parse
|  -n NAME, --name NAME  project name
|  -d DIR, --dir DIR     templates directory

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@sacred.ru>
yoda: Add the --output option

This one specifies the output files. For C code parser the
argument should be "<h_file>:<c_file>" string.

Signed-off-by: Pavel Emelyanov <xemul@sacred.ru>
yoda: Add --generate option

This one says what to generate. If not given, yoda file is just
checked for validity.

Available generators for now -- cparser

Signed-off-by: Pavel Emelyanov <xemul@sacred.ru>