Replace sqlite3_open usages by sqlite3_open_v2
Add DatabaseConnection.last_insert_rowid
Add PreparedStatement.bind_parameter_count
Check that all parameters are bound in bind_values.
Add DatabaseConnection.busy_timeout.
Add DatabaseConnection.trace
Split PreparedStatement.execute into exec/exec_query
Improve error handling.

Replace SqliteError enum by a struct.
Fix DatabaseConnection.new
Add extended result code to SqliteError.
Merge branch 'master' of https://github.com/gwenn/rust-sqlite3

Conflicts:
	src/core.rs
	src/types.rs