beast cleanup and tidying:

* Replace custom types with C++11 <cstdint> types
* Fix sqlite integer intos and uses
* Fix String implicit integer constructors
* Escape the enclosing namespace in sqdb
* Replace contract checks with assert
* Make many header files compile independently
* Remove the dependence on beast_core.h in many places
* Remove unused or obsolete classes and functions
* Remove unused or obsolete macros
* Remove unused network functions and files
* Remove unused or obsolete classes:
  - ChildProcess
  - HighResolutionTimer
  - InterProcessLock
  - Throw
  - TrackedMutex
  - UntrackedMutex
  - XmlDocument
  - XmlElement

src/ripple_data/crypto/RFC1751.cpp

@@ -487,7 +487,7 @@ void RFC1751::getEnglishFromKey (std::string& strHuman, const std::string& strKe
 
 beast::String RFC1751::getWordFromBlob (void const* data, size_t bytes)
 {
-    beast::uint32 hash;
+    std::uint32_t hash;
 
     beast::Murmur::Hash (data, bytes, 0, &hash);