HaikuBook: fix warnings generated by Doxygen 1.18.16.

This version generates some warnings and identified some problems in our
documentation. It is also a bit more vigilant about undocumented elements, so
these are now decorated with a brief description. In the BNotification docs I
used a stray \p to create some whitespace between code and an image. This is
now fixed in the CSS instead.

Fix BMimeType::SetIconForType() docs

Documentation updates for Storage Kit classes

* Added \since to each method and parameter.
* Whitespace cleanup.
* Some other minor cleanups and updates.

Move documentation from NodeInfo into the API docs.

* Delete the docs from NodeInfo.cpp and NodeInfo.h
* I snuck a couple of style fixes into NodeInfo.cpp
* I had to make a small modification to MimeType.dox to prevent it
from overriding the docs of one of the methods in NodeInfo.dox.

Big docs cleanup.

* Fixed headers including:
- All rights reserved not All Rights Reserved.
- name, email@domain.com not name <email@domain.com>
- tabs and spaces
- Authors: not Documented by:
* Renamed string.dox to String.dox
* Renamed midixxx.dox files to MidiXxx.dox
* Moved images into images subdirectories and updated Doxfile.
* Re-format all files with tabs instead of spaces.
* Fix many spelling mistakes.
* Added all files, classes, structs, and enums to libbe group.

Fix another warning in MimeType.dox along with some 80 char fixes

Fix 2 warnings in MimeType.dox

Remove MimeType docs from MimeType.cpp and cleanup style issues in that file. Create a MimeType.dox file and add the docs there.

Fix BMimeType::SetIconForType() docs

Documentation updates for Storage Kit classes

* Added \since to each method and parameter.
* Whitespace cleanup.
* Some other minor cleanups and updates.

Move documentation from NodeInfo into the API docs.

* Delete the docs from NodeInfo.cpp and NodeInfo.h
* I snuck a couple of style fixes into NodeInfo.cpp
* I had to make a small modification to MimeType.dox to prevent it
from overriding the docs of one of the methods in NodeInfo.dox.

Big docs cleanup.

* Fixed headers including:
- All rights reserved not All Rights Reserved.
- name, email@domain.com not name <email@domain.com>
- tabs and spaces
- Authors: not Documented by:
* Renamed string.dox to String.dox
* Renamed midixxx.dox files to MidiXxx.dox
* Moved images into images subdirectories and updated Doxfile.
* Re-format all files with tabs instead of spaces.
* Fix many spelling mistakes.
* Added all files, classes, structs, and enums to libbe group.

Fix another warning in MimeType.dox along with some 80 char fixes

Fix 2 warnings in MimeType.dox

Remove MimeType docs from MimeType.cpp and cleanup style issues in that file. Create a MimeType.dox file and add the docs there.