[JENKINS-15382] no longer only about UTF-8

(cherry picked from commit 59f0f32ff63d081475e5c691a8c932d98f688101)
[FIXED JENKINS-15382]

Revisiting the fix. Avoid parsing the entire text by only looking at the tail portion.

(cherry picked from commit 14d980c4377dc703df8db76f192de19246a0266e)
[JENKINS-15382] Forgot to close the file

(cherry picked from commit 43ecda6d2d4aba44144d12fb89ad1ed3e77bc7f3)
[JENKINS-15382] not sure which code is triggering animal sniffer violation

(cherry picked from commit f7671e621e374bc51a81ec75c056d15ee359093a)
[JENKINS-15382] removed Java 1.6 dependency

(cherry picked from commit 82404407f2c26b3b0509e392ec35dee8ea7dc571)
[FIXED JENKINS-19171] Identify user agent for Internet Explorer 11.

(cherry picked from commit a184ef54cd9da5b2e20ca0bc31c53e99c5793741)
[FIXED JENKINS-18775] Integrated XStream 1.4.4-jenkins-4 with attempted fix for race condition.

(cherry picked from commit 89c94dda875fba273d22451c540c2ad9e4ac0197)
[JENKINS-17248] Be robust against exceptions in ItemListener.onLoaded, since this could interrupt Jenkins startup.

(cherry picked from commit 4def416224074c611f41185bd4e2dd0b68bcba5d)
[FIXED JENKINS-7291] Permit flyweight tasks to run on master even when it has zero configured executors.

Always adding Computer for master as a fallback

The original proposed fix for JENKINS-7291 creates a Computer object
transitively. This seems unwise as it violates the design of Computer
as stated in the javadoc, and for example we can end up creating two
Computers for the master.

I think a better fix is to create a Computer for the master all the
time, even if there's no executors configured. The discrimination in
Queue.makeBuildable would ensure that such phantom Computer is only used
as a last resort (statistically speaking).

I've also tweaked executors.jelly a bit. I simplified it somewhat
based on the idea that "if there's only one computer to show, the
context is likely making it obvious".

(I must be missing the intricacy in the current code.)

Originally developed in a branch at
2c5b57fcc1f39ed39057254e802f4183db5aa0dc then squashed for clarity.

(cherry picked from commit a114c693bc61c564232e78c9fffb5de1ef946ea8)

Conflicts:
	changelog.html
[FIXED JENKINS-17983] Empty LogRecorder.Target.name was not working.
(cherry picked from commit 84d1abdcd42ab64198a29a40bdec268eac384b22)

Conflicts:
	changelog.html
[JENKINS-17575] Baseline testing of behavior without folders.
(cherry picked from commit dcff6e41302093b6ba90da0aa6e9b09a5cfe2b86)
[FIXED JENKINS-17575] Redirecting properly after deleting jobs in folders.
Expanded MockFolder to be a ViewGroup so that it is possible to test views inside folders,
and generally fixed it to service Stapler hierarchies properly so that WebClient-based tests can work.
(cherry picked from commit 1205e9f6c492c53983a7f02926a53739b50b92fd)