Issues resolved in 5.2.0

Modem failed to properly send/receive break signals.
Implemented "/" command within command string for 125ms delay.
Implemented latest fax code from base branch.
Improved flow control (hardware and software) process when in fax mode.
Corrected numeric response codes (V0).
Corrected erroneous error count in &T8 test.
Improved GSTN cleardown message for non-ARQ connects.
Unsolicited response messages (RING/CID) failed to use correct baud/parity settings upon powerup.
Lower &Nx settings kept v34 data modulation disabled.
Corrected s32 register disabling v90 when proper value was set.
Corrected &U functionality in PCM mode.
Corrected autobaud function on subsequent "AT" commands after DTE rate change.
Modem would not respond if commands were sent while DTR signal was low.
Corrected DTE rate limiting connect rate when remote is PCM capable.
Corrected excessive rateshitfts on clean lines in PCM mode.