Call AM_INIT_AUTOMAKE once

It is actually invalid to call AM_INIT_AUTOMAKE several time, and
provokes an error.
updated OSX build doc to use Autotools (easier)
Add doc to build on gentoo with overlay
highly experimental soft checkpoint based on consensus
Merge pull request #99 from toyg/new_osx_build_doc

updated OSX build doc to use Autotools (easier)
Merge pull request #98 from jd/jd/fix-build

Fix AM_INIT_AUTOMAKE call
Merge pull request #104 from ddorian1/doc

Overlay for gentoo
fix typo, add Troubleshooting, simplified install

... html ui, replace *.git repos url to https:// repos
add libtool

fix #108
Correcting autotools.sh to autotool.sh

The docs say ./autotools.sh but the file is named autotool.sh
Merge pull request #107 from iShift/patch-1

fix typo, add Troubleshooting, simplified install
Merge pull request #109 from iShift/patch-2

add libtool
Merge pull request #118 from ezrafree/patch-1

Correcting autotools.sh to autotool.sh