fix log wording
Adds read_all method to iostream transport

Adds `connection::read_all(...)` method to iostream transport as a
convenience method for reading all data into the connection buffer
without the end user needing to manually loop on `read_some`.
add documentation for socket policies
clarified documentation for bad_connection error
add docs for namespaces and concurrency policies
Added a semicolon.
Merge pull request #359 from redboltz/add_semicolon

Added a semicolon.
Merge remote-tracking branch 'mainstream/master'