some language issues fixed

[JENKINS-26684] Escape special chars in maven build step arguments

[FIXED JENKINS-25953]Tabs in job view are layouted in wrong way

Fix few tests on windows

Update README with minor grammatical fix

Removed an extra 'of' in line#5 to fix the sentence structure.
BEFORE: 'and a number of other "of" contributors
PROPOSED: and a number of other contributors

[FIXED JENKINS-26406] Build history text field wrap fails when containing markup

[FIXED JENKINS-26718] Update changelog

JenkinsRule does the same for years.

Bump powermock to 1.5.6 that support java 8

[JENKINS-26755] cache node environment

Added test for env var expansion in SimpleBuildWrapper

to prevent inefficient channel overuse

[JENKINS-26718] OldDataMonitor: Handle poorly written project types

[FIXED JENKINS-26601] Partly reverting #1453 to avoid hitting https://github.com/google/guice/issues/899.

(cherry picked from commit 00c858d4 into 1.599 rc)

In this environment, Util.createSymlink and .isSymlink are implemented, but resolveSymlink is not.
(cherry picked from commit 388c4b5e)

Conflicts:
	changelog.html

(cherry picked from commit 75c8c31f)

(cherry picked from commit 0633beef)