Added new files and updated the readme file.

* New file Makefile with support for downloading and building the actual RPi
  kernel and building the module modrss.
* New file modrss.c, the module source file.
* New file modrss.h, the module header file.
* New file setenv.sh for configuring the buidl environment.
New file .gitignore.
Add fully functional driver modrss

* Remove header file.
* Add possibility to change the default GPIO by module parameter.
* Change function ordner so that no prototyping is needed.
* Remove not needed debugging output.
* Add copy_from_user call to read socket switch command from user space.
Minor changes to modrss.c
modrss.c

* Change pr_info to pr_error where reasonable
* Add default tree to encoder selection. This will be triggerd if user
  entered a not known encoder type.
Add check for user data gained from user space
Change some comments
Change Makfile to compile with debug flag
Change some pr_info statements to pr_debug
Change check for valid GPIO pin

* Use macro ARRAY_SIZE instead of self-calculating the array size
Change Makefile to use kerneldir inside ~/hackstock/kernelbuild
[modrss.c] Change to misc char driver interface
[modrss.c] Fix typo
[modrsswitch.c] Fix "missing or wrong GPIO parameter" output
[modrss.c] Fix exit function to deregister misc char device
[modrss.c] Do some code cleanup

* Remove not needed functions
* Remove not needed variables
* Fix "C90 forbids mixed declarations and code" warning
[modrss.c] Remove debugging output which might influence the timing
[modrss.c] Introduce a define for the pulse length
[modrss.c] Do checkpatch cleanups
[modrss.c] Change codeword variable to be initialized at runtime