Update install-sx.sh

Made the install script multi-OS friendly, and also added some compilation tips for less experienced users.
clarify error message
Add libobelisk CFLAGS to AM_CPPFLAGS

This fixes a build failure when libobelisk is installed in a non-standard location.
Merge pull request #7 from veox/master

Update documentation with new repo link
fix order of magnitude error in mktx usage
Merge pull request #10 from ryancdotorg/patch-2

fix order of magnitude error in mktx usage
Fixed cpu usage bug where floating point values inside sleep are rounded down to 0.

Replaced sleep(0.1) to msleep(100)

Thanks to AgentME
msleep -> usleep
changed to usleep in history.cpp
install-sx workaround for libconfig++8-dev packages.
additional update.
organise commands into categories (thanks to tphyahoo from Freenode IRC)
remove debug line.
added libwallet to sx. functionality from libbitcoin that is not core will be forked into libwallet from now on.
fix compile errors due to libwallet port.
"most commonly used commands" -> "commands" since it's a full list.
Merge pull request #3 from ryancdotorg/patch-1

clarify error message
Merge branch 'patch-1' of git://github.com/hughpearse/sx into hughpearse-patch-1

Conflicts:
	install-sx.sh
Merge pull request #4 from jonls/makefile-fix

Add libobelisk CFLAGS to AM_CPPFLAGS
PabloCatellano: Use AM_SILENT_RULES during building