* Replace connection handle method check_connection() with is_connected() and ping_server()
* When a connections is fetched from a pool perform a validity check which can be one of none, passive or ping.
* Add the methods is_connected() and ping_server() to the connection template class.
* Remove unused #include and add mising #include.
* Add tests for the connection methods is_connected() and ping_server().
* Move the code for sqlpp::sqlite3::detail::prepared_statement_handle_t to include/sqlpp11/sqlite3/detail/prepared_statement_handle.h
* Whitespace
* Move the code for sqlpp::sqlite3::detail::connection_handle to include/sqlpp11/sqlite3/detail/connection_handle.h
* Rename sqlpp::sqlite3::serializer_t -> sqlpp::sqlite3::context_t
* Add const qualifiers to sqlpp::mysql::context_t::escape() and its parameter.
* Change method argument types "const std::string" -> "const std::string&"
* Remove a superfluous function that forwards the call to sqlite3_close().
* Move initialization of sqlpp::sqlite3::detail::prepared_statement_handle_t data members from the constructor into the member initialization list.
* Rename method parameter from CamelCase to snake_case.
Add support for connection pooling
* Add support for connection pooling to the core code.
* Add support for PostgreSQL connection pooling with tests.
* Add support for SQLite3 connection pooling with tests.
* Add support for MySQL connection pooling with tests.
* value: add missing includes
* mysql, sqlite3: use explicitly *out* stringstreams for serialization
* postgresql: fix: use max_digits10 instead of digits10
* detail: add float_safe_ostringstream, ensuring floats are serialized with enough precision
* mysql, postgresql, sqlite3, tests: fix: set float-precision for all streams
* run clang-format on changed files
* inline remove_cvref.h
* replace unspecific "wrapper" with concrete type name
* tests: split connector specific tests out of serialize/Float
Leak: The sqlite3 connection handle destructor was
accidentally turned into a default constructor during the
migration of repositories.
Replaced the sqlite3 raw pointer with a unique_ptr to prevent
this kind of accident.
Add Connector Cmake logic
* Also install date when used with fetch content
* Install everything always
* Update documentation
* Add option to control dependency searching
* Adjust travis
Changed sqlite3 usage tests to be linked into one executable.
This provokes multiple definition errors for non-inlined free
functions.
Also ran clang-format on the changed headers.
