Buxton Simple

Added getters and modified setters to take in fewer arguments.
Added structures to get values and status to enable setting errno.
Errno now can be checked by the programmer when getting/setting a value.
New function buxtond_set_group, changes the group and creates it.
Created universal callback functions for set_value and get_value
for BuxtonDataTypes.

Added in test file lbuxton-simp_test.c separate from library
lbuxton-simp.c.