[reSIProcate] SDP and STL usage

[Cullen Jennings <fluffy@xxxxxxxxx>]

Codec defined a hashmap based on Codec and also depends on Medium, Medium
defines a hashmap based on Codec. This is not going to be a happy thing for
HashMap implementations that have a size that depends on the size of the
stored items. 

The code had static initializes that build a hashmap.