Added functions to query depth, ir and color frame count.

[nylocx]

This new functions can be used to determin the end of an .oni file stream.

[jspricke]

+1

[taketwo]

Could you please do the following:

• Format according to the PCL style guide
  • use double space for indents
  • add spaces between function names and braces
  • put { on separate lines
• Add a short doxygen comment explaining what is returned by the functions. (I.e. that 0 means that it is a real device, not a file. Also if it is the total number of frames in the file or the remaining number of frames.)

[nylocx]

I tried to adjust the patch according to your comment.

[taketwo]

I think there are still spaces missing in the header file. When you fix it please also squash the commits so we get a clean history. Thanks!

[nylocx]

Ok, yeah missed the header spaces, btw. is there a good reason for this coding style with spaces after functions? I have not seen that very often.

[taketwo]

I guess it was a random choice made by the founder of the library. Yeah, it's not very common and certainly makes maintainer's life harder :)

[jpapon]

Spaces after functions isn't random, it's part of the GNU coding standards =)

Also, be careful, Radu might be listening!