Switch to arc-snps-linux-uclibc target triplet

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
windows: Add weblinks to wiki and releases

Add shortcuts to Wiki page and Releases page to the Start Menu.

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Version of toolchain scripts to use combined binutils-gdb repository

	* README.md: Updated for unified binutils-gdb repository.
	* arc-clone-all.sh: Likewise.
	* symlink-all.sh: Avoid sim and gdb directories in binutils
	trampling on gdb versions.
Deal with the GDB clashing tag names.

	* tag-release.sh: Use a separate tagname for GDB.