0.4.4

• fixed bug where frequency set by MAC commands was 1/100th of the required value (i.e. I forgot to multiply by 100).
  This affected rxParamSetup, newChannel, and dlChannel commands. It's likely no-one has ever used
  this feature.
• added code to previously empty LDL_Region_validateFreq() to check centre frequency is within bounds for a given region
• changed setChannel() to call LDL_Region_validateFreq() to guard against illegal channel settings
• fixed bug in restoreDefaults() where region will always be set to zero
• refactored restoreDefaults() into separate initSession() and forgetNetwork() functions
• fixed bug where ctx.rx2Rate is used instead of ctx.rx2DataRate on receive
• removed rx2Rate from session struct which appears to be duplicate of rx2DataRate
• added debug code to print session to trace