Fix documented Composer home variable name
added --no-progress to self-update

closes composer/composer#3555
Merge pull request #3556 from alcohol/add-option-no-progress-to-selfupdate

added --no-progress to self-update
Merge pull request #3554 from loonies/doc-fix-variable

Fix documented Composer home variable name
Also detect full temp dir, fixes #3559
Load plugins before purging packages, fixes #3557
Fix activation of global plugins, fixes #3557
Add --absolute to resolve absolute paths in config command, otherwise set default back to relative
Fix parsing of empty git commits, fixes #3565
Fix relative path fetching when a var uses var replacement, fixes #3564
Minor fix to the HTTP Basic Authentication documentation

Replaced JSON array with JSON object since you cannot assign key values in an array.
Merge pull request #3567 from tomzx/patch-1

Minor fix to the HTTP Basic Authentication documentation
Add a failing testcase for stability flags in complex constraints

Refs #3570
Support parsing stability flags on complex constraints

Fixes #3570
Merge pull request #3583 from stof/complex_stability_flag_issue

Fix the parsing of stability flags on complex constraints
test under lowest deps