lexer: Clean up warnings
struct: Remove the unused "second" expression
db: initialize 'values' variable to silence the warning in DBSERVER_OBJECT_SET_FIELD_IF_EMPTY
shutdown: Fix the overloaded function
ca: Another overloaded function fix
ca: Initialize key_error
Try using virtual method calls (w/ fixed prototype for what()).
BugFix: Fix incorrect method signature for ShutdownExeption::what
Merge pull request #264 from Astron/osx/warning-fixes

OS X: Warning Fixes
Merge branch 'master' into feature/async_write