Implement aliases using a hashmap

[jovanbulck]

For elegance and efficiency, we should probably change the datastructure for aliases from a linked list of structs to a hashmap<char *key, char *value>

As far as I know, there's no native support in libc for hashmaps. We should probably look to an optimized GPL licensed hashmap implementation and include it in the project...

[jovanbulck]

Some candidates:

• http://www.mission-base.com/peter/source/
• http://stackoverflow.com/questions/1138742/looking-for-a-good-hash-table-implementation-in-c#8470745
• http://stackoverflow.com/questions/18197825/looking-for-hash-table-c-library#18205028
• http://troydhanson.github.io/uthash/