Version 2.0.0

• New major release 2. API and ABI are not backwards compatible with version 1,
  hence the new soname - libacars-2.so.2. Header files are now installed to
  /usr/local/include/libacars-2. New pkg-config script libacars-2.pc provides
  updated compiler and linker flags. Version 2 can be installed in parallel with
  version 1.
• New feature: generic engine for reassembly of fragmented messages. Supports
  automatic tracking of fragments' sequence numbers (with possible wraparounds),
  handles reassembly timeouts and fragment deduplication. Messages can be keyed
  with arbitrary data (eg. custom header fields).
• New feature: automatic reassembly of ACARS messages. New function
  la_acars_parse_and_reassemble performs both parsing and reassembly, while
  existing la_acars_parse function performs parsing only and works as before.
• New feature: automatic reassembly of MIAM file transfers. New function
  la_miam_parse_and_reassemble performs both parsing and reassembly, while
  existing la_miam_parse function performs parsing only and works as before.
• New feature: pretty-printing of XML text in ACARS and MIAM CORE payloads.
  If the message text is identified as XML (ie. it parses without errors),
  la_acars_format_text and la_miam_core_format_text routines will print
  it with proper indentation for better readability. The feature is optional,
  depends on libxml2 and must be turned on by setting prettify_xml
  configuration variable to true.
• New feature: simple hash table implementation. Mostly used for libacars internal
  purposes, but it's exposed in the API and can be used for any purpose.
• New feature: when compiled with debugging support, debug output to stderr is
  now configurable with LA_DEBUG environment variable. Set it to the desired
  verbosity level - from 0 (none) to 3 (verbose). The default is 0 (debug output
  suppressed).
• Incompatible change: new library configuration API. la_config structure
  with static fields has been removed. Configuration variables are now
  stored in a hash table, read with la_config_get_* and set with
  la_config_set_* functions. Refer to doc/API_REFERENCE.md for details.
  Refer to libacars/config_defaults.h for the most current list of
  configuration options and their default values.
• Incompatible change: ACARS parser now strips sublabel and MFI (Message
  Function Identifier) fields from the message text, if present. Their values are
  stored in la_acars_msg structure in sublabel and mfi fields. In text
  and JSON output they are printed as separate fields.
• Incompatible change: MIAM parser and ARINC-622 ATS message parser now expect
  sublabel and MFI fields to be stripped by the caller, otherwise the parser
  will ignore the message. This operation can be performed with minimal fuss
  using la_acars_extract_sublabel_and_mfi function.
• Incompatible change: la_miam_parse function prototype has changed. All
  parameters except txt (message text) have been removed.
• Incompatible change: no field of la_acars_msg structure has been removed.
  MSN is now stored in two fields: msg_num (first three characters)
  and msg_num_seq (last character, ie. sequence indicator).
• Incompatible change: Media Advisory message timestamp and version are now
  stored as numbers, not characters. Type of hour, minute, second and
  version fields in la_media_adv_msg structure has been changed from char[]
  to uint8_t. Relevant JSON keys have changed types as well.
• Incompatible change: state and current_link fields in la_media_adv_msg
  structure changed from char[2] to char, hence their values are no longer
  NULL-terminated.
• examples: media_advisory app has been removed. Use decode_acars_apps instead.
• Bugfixes, code cleanups.