Update quickstart.md

There is no Security Group, Network, or Subnet in this blueprint. There is only one VM.
Update quickstart.md

I added two short introductory notes to deployments and blueprints.
I also corrected the number of nodes described in the singlehost blueprint, fixed a few misspelled words, and fixed one or two typos.
Update installation-general.md

Added prerequisite for 64-bit
first iteration + some fixes in terminology
some more fixes
review fixes
Merge pull request #185 from cloudify-cosmo/dsl-spec-plugins

first iteration + some fixes in terminology
Merge branch 'master' into review-guide-quickstart

Conflicts:
	guide/3.1/quickstart.md
Merge pull request #168 from cloudify-cosmo/installation-general

Update installation-general.md
Merge pull request #161 from cloudify-cosmo/review-guide-quickstart

Review guide quickstart
Merge branch 'master' into CFY-1746-nodecellar-upgrade

Conflicts:
	guide/3.1/quickstart.md