channel_variable: sdp_m_per_ptime
Adds a new m= line for each distinct ptime in codec list.

When this variable is not set:
	When mixing codecs with various ptime in a codec list, they will now be allowed to co-exist in the sdp but it will send no ptime attr.
		This means the ptime preferences on the offer will be ignored when mixing codecs with various ptimes.
	When receiving a codec list with no ptime attr, the ptime will be chosen from local preference instead of assuming 20ms
		This means if offer contains PCMU with not ptime and FS has PCMU@40i

Dynamic payloads will now start at 98 and increment per additional dynamic codec per call.
	So now you can add CELT@32000h,CELT@48000h and each one will be auto-assigned a dynamic paylaod type.

FS-2776: FS uses IPv6 under Proxy mode, and SIP Phone uses 6to4 tunneling IPv6 address, cause hearing nothing.

FS-2777: You know this is only an example of how to use FreeSWITCH, this config needs to be rewritten its turning into a beast

set idle pattern to 255 instead of 0 to prevent clipping sound on short frames from mod_native_file FS-2772

freeswitch.spec moved to support freetdm instead of openzap including hooks to compile with libsng_isdn and wanpipe. Added mod_silk, mod_codec2 mod_cidlookup, mod_mp4v. Added runtime requirements and build dependencies. This one is a major change