3.18-stable patches

3.18-stable patches

added patches:
	ext4-add-corruption-check-in-ext4_xattr_set_entry.patch
	ext4-add-more-inode-number-paranoia-checks.patch
	ext4-always-check-block-group-bounds-in-ext4_init_block_bitmap.patch
	ext4-always-verify-the-magic-number-in-xattr-blocks.patch
	ext4-avoid-running-out-of-journal-credits-when-appending-to-an-inline-file.patch
	ext4-fix-check-to-prevent-initializing-reserved-inodes.patch
	ext4-fix-false-negatives-and-false-positives-in-ext4_check_descriptors.patch
	ext4-never-move-the-system.data-xattr-out-of-the-inode-body.patch
	ext4-only-look-at-the-bg_flags-field-if-it-is-valid.patch
	jbd2-don-t-mark-block-as-modified-if-the-handle-is-out-of-credits.patch