Add explicit cast in the definition of HPP_ASSERT because C++11 does not
accept implicit conversion from shared_ptr to bool.

	* include/hpp/util/assertion.hh,
	* include/hpp/util/exception.hh: Fix support for extra
	qualifier in generated exceptions (i.e. for visibility support).
	* src/Makefile.am: Fix typo.
	* tests/exception.cc: Do not use extra qualifier here to
	generate the exception.
Signed-off-by: Thomas Moulard <thomas.moulard@gmail.com>

	* include/Makefile.am: Distribute new header.
	* include/hpp/util/assertion.hh: New.
	* include/hpp/util/exception.hh: Do not include symbol
	visibility information when generating a class.
	* tests/Makefile.am: Compile new test case.
	* tests/assertion.cc: New.
	* tests/assertion.stdout: New.
	* tests/testsuite.at: Run new test case.
Signed-off-by: Thomas Moulard <thomas.moulard@gmail.com>