Fix errors in generated code when MAVLINK_CRC_EXTRA is disabled

Also ensures that packet length parameters use the appropriate *_LEN define
instead of hardcoding the raw values.
Clarified units for latitute/longitude/altitude in various messages.
Python generator: allow for hex and binary notation in enum value attributes (and longer ints).
Fixed error received when running mavlogdump.py when processing invalid messages that contained a non-ASCII value.
Merge branch 'master' of https://github.com/mavlink/mavlink into inv_char_fix
Merge pull request #119 from Susurrus/inv_char_fix

Fixed issue with printing MAVLink_bad_data
Merge pull request #118 from AutoQuad/upstream

Python gen: allow for hex and binary notation in enum value attributes
Merge pull request #113 from Susurrus/new_issue_92

Clarified units for latitute/longitude/altitude in various messages.
Merge pull request #106 from RFDesign/upstream

Fix errors in generated code when MAVLINK_CRC_EXTRA is disabled
Permits external m_mavlink_status array.
Added a message encoding function that accepts a channel.

In the C-API, just like there are the `mavlink_msg_msgname_pack` and `mavlink_msg_msgname_pack_chan` functions, there should be  `mavlink_msg_msgname_encode` and `mavlink_msg_msgname_encode_chan` functions, as not all messages are sent over the MAVLINK_COMM_0 channel and need the appropriate sequence number set.
message_defintions: added RADIO_STATUS, SIM_STATE and HIL_SENSOR

the RADIO_STAUS is a copy from ardupilotmega

HIL_SENSOR is intended to replace HIL_STATE, giving missing
information

SIM_STATE is used to provide feedback to ground stations on true SIM
state

Pair-programmed-with: Lorenz Meier
re-generate for new msgs
fix gen_all.sh for uppercase Python
pymavlink: re-generate python modules
fixed typo in ardupilotmega.xml
mavutil: added check_condition() method
mavutil: added MAVLink broadcast support
mavextra: use rotmat method of tilt compass calculation
pymavlink: added code to support mode change by name