Update changelog for 1.7.3
Merge branch '1.7' into 1.8

Conflicts:
	docs/changelog.rst
Add 1.8.3 to changelog
Merge branch '1.8'

Conflicts:
	docs/changelog.rst
Update Releases requirement for needed bugfixes
Merge branch '1.7' into 1.8
Merge branch '1.8'
Modified changelog w/o releasing...
Merge branch '1.7' into 1.8

Conflicts:
	docs/changelog.rst
Merge branch '1.8'
Bump 1.7.3 for setup.py tweak
Merge branch '1.7' into 1.8 & cut 1.8.3

Conflicts:
	fabric/version.py
Merge branch '1.8'
Permit Paramiko >=1.13 under Python 2.6+

Re #1105
Changelog re #1105, fixes #1105
Merge branch '1.7' into 1.8

Conflicts:
	docs/changelog.rst
Merge branch '1.8'
Merge remote-tracking branch 'upstream/master'