THRIFT-2912 Autotool build for C++ Qt library is invalid
Client: C++
Patch: Nobuaki Sukegawa <nsukeg@gmail.com>

This closes #336

* Fix incorrect AC_PATH_PROGS usage
* Exclude generated source code from distribution
THRIFT-2910 libevent is not really optional
Client: C++
Patch: Nobuaki Sukegawa <nsukeg@gmail.com>

This closes #337