Bump version.

bfd/
2017-07-25  Tristan Gingold  <gingold@adacore.com>

	* version.m4: Bump version to 2.28.2
	* configure: Regenerate.

binutils/
2017-07-25  Tristan Gingold  <gingold@adacore.com>

	* configure: Regenerate.

gas/
2017-07-25  Tristan Gingold  <gingold@adacore.com>

	* configure: Regenerate.

gprof/
2017-07-25  Tristan Gingold  <gingold@adacore.com>

	* configure: Regenerate.

ld/
2017-07-25  Tristan Gingold  <gingold@adacore.com>

	* configure: Regenerate.

opcodes/
2017-07-25  Tristan Gingold  <gingold@adacore.com>

	* configure: Regenerate.