Added structure methods, Added separate memory allocator

Structure methods added
- size() gives the size of the grid
separate sources added
Separate methods for initializing and filling arrays
Added infrastructure for handling sources

* Added Devicesources.h file which stores info about devicesources
* Added Hostsources.h which stores infor about host sources
Added kernel to handle the sources  100ms shaved Yay!

* constant sources handled.
Sinusoid sources added