Bumped the version number from Contiki 2.6 to Contiki 2.7
Merge pull request #402 from adamdunkels/release-2-7

Bumped the version number from Contiki 2.6 to Contiki 2.7
added u-mote examples and platform with 8051 banking workaround
added rime examples for u-mote
adding a missing u-mote platform makefile
preliminary test of SPI driver for CC253x
removing dpi-arch and integrate spin driver to CC253x cpu
initial commit of LSM330DLC sensor

TODO: writing SPI architecture interface for every SPI connected sensors
LSM330DLC driver (unfinished) and SPI driver clean up
LSM330DLC gyro reading at 400Hz SPI speed (still buggy)
cleaning up SPI driver, added LPM 2 support
merged changes, fixed conflicts

merged changes from release-2-7 and resolving conflicts
deleted tools/mspsim subdirectory
added changes to comply with version 3.x