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

modules/beast_sqdb/source/ref_counted_statement.cpp

@@ -57,11 +57,9 @@
 */
 //==============================================================================
 
-namespace sqdb
-{
-
-namespace detail
-{
+namespace beast {
+namespace sqdb {
+namespace detail {
 
 ref_counted_statement_base::ref_counted_statement_base(session& s)
     : m_refs(1)
@@ -122,6 +120,6 @@ void ref_counted_statement::final_action()
     m_st.clean_up();
 }
 
-}
-
-}
+} // detail
+} // sqdb
+} // beast