[FIXED JENKINS-19251] Use hashes rather than modification time to determine if Maven agent JARs are up to date.

move environment in maven project to same location as in freestyle project

[fixed JENKINS-19740] Added postCheckout for SCMs

- Adds an option to the Global Security screen to hide the remember me checkbox
- A crafty user could use their browser to re-insert the form field and thereby get Jenkins to set the
  remember_me cookie on their browser, but this option should cover the 99.9% case.

This reverts commit 647695e2.

[FIXED JENKINS-19613] 49c731fc made PROXY_HEADER static under the assumption that XStream would treat that like a missing field.
Unfortunately it threw an error instead, breaking startup; fixed by renaming the constant.

[FIXED JENKINS-19753] Add view link to job artifacts list

Add a "view" link to a job's Last Successful Artifacts list, just like
an individual build's Build Artifacts list has.

[FIXED JENKINS-19749] Add a -f option for following the build without passing interrupts through to the build

[FIXED JENKINS-19739] When installing a plugin and the needed dependencies have compatibility issues, warn the user

[FIXED JENKINS-19736] Installing a plugin with optional dependencies doesn't upgrade the optional dependencies when needed

[FIXED JENKINS-12629] Using jenkins-cli connecting to HTTPS port fails due to hostname mismatch in certificate.

- NoCheckTrustManager needed to implement X509TrustManager not just plain TrustManager

[JENKINS-16502] Permission to see an executor/slave

- This is an initial version of the feature.
- The information about slave names is still exposed via label autocomplete

Suppressed a confusing 2nd error message.