Several small fixes

I have started reading your code and I have done my first commits to bellbird. Feel free to merge the changes you want. I will be really happy to discuss and comment anything :-)

Also, if you prefer I can create several  different "pull requests" for the different changes instead of a big global pull request. I am not sure if it is possible to selectively accept some of the commits from a single pull request.

Take care,

Sergio

# Changes:
- Added a .gitignore file. After compiling, git lists some created files and directories as "untracked". The .gitignore file allows these files to be ignored by git.

- Updated config.guess: There was a new version and I just replaced it

- Removed config/config: You may complain about this, because it seems that you have several CFLAGS commented out. It is not usual to place autogenerated files under git, so I removed it. No big deal if you prefer to keep it. Notice that config/config now is listed at .gitignore, so if you want to keep config/config as you had it you will need to remove it from there too.

- The header  include/nitech_engine.h included a file from ../src/nitech/nitech_hidden.h. Usually "_hidden.h" files are "private headers" which are used to *compile* a library but are not required to link with it (so "_hidden.h" headers are not installed). Having a public header which depends on the private header may cause packaging trouble, as the private header would need to be installed too (i.e. belong to the "-dev" package). In summary, "private headers" may depend on "public headers" but not the opposite. In order to comply with this "rule" I had to move some of the private type definitions to the public header and include the public header at the private one.