resip/stack: DTMF: add comments about draft-kaplan-dispatch-info-dtmf-package-00

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@11041 ddefafc4-47db-0310-ae44-fa13212b10f2
resip/recon: testUA: remove duplicate definition of sleepSeconds()

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@11042 ddefafc4-47db-0310-ae44-fa13212b10f2
resip/stack: DTMF: access button as an RFC 4733 event code

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@11043 ddefafc4-47db-0310-ae44-fa13212b10f2
resip/stack: DTMF: remove duplicate code, use skipEol() from SdpContents

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@11044 ddefafc4-47db-0310-ae44-fa13212b10f2
travis: build recon in CI

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@11045 ddefafc4-47db-0310-ae44-fa13212b10f2