scripts: add support for building manuals

Add support for building the HTML and PDF manuals for the major
components. Implement for binutils, GCC, GDB, and GLIBC.

Always build all manuals and install a subset. Be explicit about the
subset to reduce the clutter and to avoid getting copies of common
manuals like bfd from all of the sourceware based components. Downside of
being explicit is that you need to update it when a new component
comes along.

Build the manuals as part of the last GCC build, namely 'cc' for glibc
based ones and cc_core_pass_2 for baremetal.

An example of the output is at:
http://people.linaro.org/~michaelh/incoming/crosstool-NG/

Signed-off-by: Michael Hope <michael.hope@linaro.org>
[yann.morin.1998@anciens.enib.fr: depends on ! remove docs; gold manual install]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

reporter_name="Anthony Foiani <anthony.foiani@gmail.com>"

reporter_url="http://sourceware.org/ml/crossgcc/2010-09/msg00100.html"

reporter_comment="This is a sample config file for Freescale e500v2 processors (e.g., MPC8548,

MPC8572). It uses eglibc (for e500/SPE patches) and a recent gcc (4.6.0,

for e500v2 DPFP support) and will generate appropriate dual-precision

floating point instructions by default.

Note: If building a Linux kernel with this toolchain, you will want to make

sure -mno-spe AND -mspe=no are passed to gcc to prevent SPE ABI/instructions

from getting into the kernel (which is currently unsupported). At this time,

the kernel build system properly passes those two options, but older kernels

were only passing -mno-spe by default."