Transactor refactor:
* Allocate transactors on the stack instead of the heap.
* Remove header files and reduce transactor public interface.
Ticket issuing (RIPD-368):
* New CreateTicket transactor to create tickets
* New CancelTicket transactor to cancel tickets
* Ledger entries for tickets & associated functions
* First draft of M-of-N documentation
Ticket integration tests
Cleanups to RPC code
Cleanups and fixes (RIPD-532):
* Properly handle sfWalletLocator field
* Plug a tiny memory leak
* Avoid naked pointers
* Remove unused variables
* Other small cleanups
Add date to tx command (RIPD-542)
Create the directory for the debug_logfile (RIPD-551)
Increase the size of the tree cache:
This change will not significantly increase memory consumption
because most entries are pinned anyway.
Make more RocksDB tunables
Add support for universal compaction
Refactor LedgerEntrySet:
* Split adjustOwnerCount to increment and decrement paths.
* Move pathfinding-specific functions out of LedgerEntrySet
* Convert members to free functions
Improve regularity of STObject and STArray (RIPD-448, RIPD-544):
* reduce duplicated code using templates
* replace BOOST_FOREACH with C++11 for loops
* remove most direct calls to new
* limit line length to 80 characters
* clearly identify virtual and overridden methods
* split STObject and STArray into their own files
* name files after the class they contain