This commit enforces naming style for Classes and global constants:
Camel_Snake_Case for Classes
UPPER_CASE for global constants
CamelCase for abstract classes
Adds GLONASS L2 C/A signal processing to GNSS-SDR based on previous
work developed for the L1 signal. All code have been added in a single
commit with the idea to illustrate the process of signal addition for
future work