Update devices/AVR8.c

fixed SS pin of an AVR set to output to prevent the master for all devices
changed contrast to hex, makes sense as the other constants are also hex
Update controllers/PCD8544.c

changed line 54 to be correct
instead of
glcd_command(PCD8544_SET_VOP | (val|0x7f))
should be
glcd_command(PCD8544_SET_VOP | (val&0x7f))
Merge pull request #1 from Mircho/master

- Initialization of the SS pin should be done for all devices
- The void glcd_set_contrast(uint8_t val) method for PCD8544 had some wrong ORing instead of ANDing
- Thanks to Mircho for the fixes
Cosmetic changes
Extra commands for ST7565R
Change VOP for PCD8544
Set AVR SS pin as output for SPI LCDs
Plus other minor cosmetic changes
Merge branch 'master' of git://github.com/andygock/glcd.git into PP_Board
Update .gitignore
Minor code cleanup (outside C99 std)
Update documentation
Minor layout changes for unit tests
Documentation update
Cosmetic change