Merge tag '0.25' into develop

Fixes for gcc-4.8 under cygwin 64bit
eval commodity function for sending commands to the database and getting the return value back
Added alias method to wrapped values so that you can select constant values
Fixed all_of(table_alias)
Fixed all_of(alias_table)

For real this time, I hope :-)
fixed static_assert message wording
Added a few missing const qualifiers
Fixed operators += et al
Added missing file
Merge branch 'release/0.26'
Merge branch 'master' of https://github.com/rbock/sqlpp11