• Changed the definition of cost basis to preserve the original cost basis
  when a gain or loss is made (if you bought 1 AAA for $10 and then sold
  it for $12, ledger would previously take $12 as the cost; the original
  cost of $10 is preserved as the cost basis now, which addresses strange
  behaviour with -B after a capital gain or loss is made).
• Incorrect automatic Equity:Capital Gains and Equity:Capital Loss entries
  are no longer generated when a commodity is sold for loss or profit.
• Support for virtual posting costs.
• The option--permissive now quiets balance assertions
• Removed SHA1 files due to license issues and use boost instead.
• Added option --no-pager to disable the pager.
• Added option --no-aliases to completely disable alias expansion
• Added option --recursive-aliases to expand aliases recursively
• Support payee uuid directive.
• Bug fix: when a status flag (! or *) is explicitly specified for an
  individual posting, it always has a priority over entire transaction
  status.
• Bug fix: don't lose commodity when cost is not separated by whitespace
• Improved backwards compatibility with ledger 2.x
• Build fix for GCC 4.9
• Build fix for boost 1.56
• Many improvements to ledger-mode, including fontification
• More test cases and unit tests
• Contrib: Added script to generate commodities from ISO 4217

⚠️ IMPORTANT ⚠️
To build Ledger from source download the ledger-utfcpp.zip and install it into the Ledger source tree, e.g.: unzip ledger-utfcpp.zip -d ledger-3.1/