use an appropriate location for system profiles on windows
move os detection into leiningen.core.utils
always process trampolines, even when used in aliases and higher-order tasks
remove unused leiningen.trampoline-file system property
Add :system to list of profiles applied by default.
Warn when system profiles contain :repositories.
Prefer ^:private to closing over an atom.

For consistency more than anything else.
Bootstrap leiningen-core with the base profile only.
Formatting for leiningen-core files.
Exclude in update-in task.
Formatting in tasks.
A few more news entries.
Move gpg setup notes from DEPLOY to GPG [fixes #1073]
Merge pull request #1077 from djpowell/windows-system-profile

use an appropriate location for system profiles on windows
Merge pull request #1078 from djpowell/more-bat-fixes

Support higher-order tasks and aliases that use trampolines in lein.bat
#949 Allow specification of artifact signing key.

Add :signing {:gpg-key "..."} option to project maps (global value)
and to :deploy-repositories maps (per-repo value). Does not yet work
in :repositories specs.

Also:
* Document per-repo :sign-releases option
* Delete unused defn deploy/signature-for
Remove outdated link to GitHub downloads page.
Tag tests which require network access.
Don't blow up when test eval-in-project doesn't return a number.

Hopefully only an issue when using :eval-in-leiningen.
Bump cheshire, slingshot, and pomegranate deps.
update java.library.path based on :native-prefix, addressing #898
document user-visible changes addressing #898