2009-08-18  Edward Smith-Rowland  <3dw4rd@verizon.net>

	include/tr1/gamma.tcc: Change include guard from _TR1_GAMMA_TCC
	to _GLIBCXX_TR1_GAMMA_TCC to match the rest of the headers in tr1.
	include/tr1/exp_integral.tcc: Replace _TR1_GAMMA_TCC with
	__numeric_constants<_Tp>::__gamma_e().