Templetize and improve beast string-to-integer conversions:
* Properly handle numbers at the edge of precision
* Improve and expand unit test coverage
Detect invalid inputs during STAmount conversion (RIPD-570):
* More robust validation of input
* XRP may not be specified using fractions
* Prevent creating native amounts larger than max possible value
* Add unit tests to verify correct parsing
On missing node in consensus, bow out (RIPD-567)
Add needed #include <istream>
This is needed for the combination of boost 1.56 and libc++
Set page sizes for ledger_data correctly (RIPD-249)
Add account_lines paging (RIPD-343)
Add account_offers paging (RIPD-344)
Improvements to SConstruct:
* Default target is release instead of debug (scons with no arguments).
* All targets now include debug symbols, including release.
Rationale: "out of the box" builds of rippled using plain "scons" or "scons -j4" will produce
a debug instead of a release build, which could underperform.
Build gcc.debug using -Og flag

Since gcc 4.8 is required anyways, it might be nice to use its features.

Intro to feature (second bullet point):
https://gcc.gnu.org/gcc-4.8/changes.html

-g (line 328) is still needed:
http://stackoverflow.com/questions/12970596/gcc-4-8-does-og-imply-g
Add +DEBUG to the raw version string for DEBUG builds.
This will show up in the rpc server_info command.
There is no impact on the version string for release builds.
Mark several Ledger member functions as const.
Decouple LedgerMaster from configuration
Distinguish Byzantine failure from tx bug (RIPD-523)
Return correct error message for invalid fields
Add --quorum command line argument (RIPD-563)
Make path filtering smarter (RIPD-561)
* Break path liquidity checking into its own function
* Measure initial quality over minimum destination amount
* Test for available liquidity
Beginning of the SIGNER_LIST_SET transaction [RIPD-479]
Initial SignerListSet transaction deserialization
Creating and destroying SIGNER_LIST ledger entry

Even though the ledger entry is going in, the actual signer list is
not part of the data.  That will get figured out next.
Serialize the SignerListArray into the ledger.