Change units on capacity in stitching extension

[Aaron Helsinger]

The capacity field in the stitching extension uses different units than in the main body of the RSpec. Change the default units in the stitching extension to kbits. Additionally, accept explicit units - e.g. G, g, Gbps, gbps, M, m, Mbps, mbps, K, k, Kbps, kbps, B, b, bps

The make coordinated changes in the stitching service, ION AM, etc.

[xyang@maxgigapop.net]

Patched both AM and SCS code and checked in the code to repositories.

[Aaron Helsinger]

Please update the wiki on how to create the stitching extension to note the default units.

[xyang@maxgigapop.net]

Added the following note in red color to bottom of some wiki pages:

Note: GENI Stitching extension uses kilobit-per-second (kbps) as default unit for bandwidth/capacity. It also accepts explicit unit like B,K,M,G, Mb, Mbps etc. The above example RSpecs originally used bps as default and have not been updated.