Added gitignore for Netbeans files and directories
Added API source files and test data type (int Wrapper)
Merge branch 'master' of https://github.com/chris-asl/doubly-linked-list-API into develop
Integrated duplicate function to the insert functions of API, and updated client files (main.c, data_type files)

Now the users create one and only dummy object and change it to their needs (integration for the insert functions)
Expanded the API, adding several functions

	Changelog:  Added these functions
		1. dll_size
		2. dll_insert_before (a specified by a key element)
		3. dll_insert_after (a specified by a key element)
		4. dll_delete_front (/head)
		5. dll_delete_back (/tail)
		6. dll_get_front (/head)
		7. dll_get_back (/tail)
		8. dll_insert_front
		9. dll_insert_back
		10. dll_append
	Information for the above, is available at both the DoublyLinkedList_ADT source and header file
	Probably a manual will be added with explicit info about each parameter
Rearranged the functions to a more logical order
Removed include directive of datatype_int header file (wasn't needed there)
Renamed data_type.c file to datatype_int.c to demonstrate the proper way to name data type related files (in format `datatype_mytype`)
Renamed main.c to demo.c as it's a demonstration of the API
Renamed member variable of the struct Datatype_int
Simplified implementation of is_equal_int and added return value for dll_init on successful allocation
Added an option to dll_print function, for whether to print the elements inline or not
Renamed dll_get_data to dll_edit_data as it better represents its functionality
Merge branch 'develop' of https://github.com/chris-asl/doubly-linked-list-API into develop

Conflicts:
	demo.c
Renamed a var in a function
Committed full documentation
Merge branch 'master' of https://github.com/chris-asl/doubly-linked-list-API
Merge branch 'develop' - public version