Avoid double-checked locking idiom; already using a ConcurrentHashMap.
A user reports a general Jenkins slowdown/hang in which one thread is locking the single builder
and for an unknown reason fails to proceed:
"Handling GET /job/…/api/python : …"
   java.lang.Thread.State: RUNNABLE
	at java.util.Arrays.copyOfRange(Arrays.java:2694)
	at java.lang.String.<init>(String.java:203)
	at java.lang.StringBuilder.toString(StringBuilder.java:405)
	at java.lang.Class.toString(Class.java:150)
	at java.lang.String.valueOf(String.java:2854)
	at java.lang.StringBuilder.append(StringBuilder.java:128)
	at org.kohsuke.stapler.export.NotExportableException.<init>(NotExportableException.java:36)
	at org.kohsuke.stapler.export.Model.<init>(Model.java:69)
	at org.kohsuke.stapler.export.ModelBuilder.get(ModelBuilder.java:48)
	- locked <0x000000054260a928> (a org.kohsuke.stapler.export.ModelBuilder)
	at org.kohsuke.stapler.export.Property.writeValue(Property.java:224)
while all other threads handling REST calls block.
No need to maintain metaClasses map if JRebel integration is inactive.
Adding hint to exception message.
Sometimes if localhost:8080 has too many cookies, CrumbIssuer will start complaining.
(Header lengths exceeded? Winstone bug?)
Annotation for filtering JSON output from js bound methods.

Handy when you want to limit the data returned from domain objects.
For example you might always want to exclude the ACL
or just the name and description on a list page and all when clicking for
details.
More configuration options for the annotation

And transient fields should be ignored by default.
doc improvement
added a mechanism to cancel the dispatch and move on to the next
doc improvements
[maven-release-plugin] prepare release stapler-parent-1.210
[maven-release-plugin] prepare for next development iteration
[JENKINS-14362] Switch to jzlib for GZIP streaming.
Back to standard version numbers.
Merge branch 'master' into JENKINS-14362-jzlib
recursively handle HttpResponse-implementing Exception
Merge pull request #16 from jglick/ModelBuilder-concurrency

Make ModelBuilder safely concurrent
Merge pull request #22 from jglick/JENKINS-14362-jzlib

Use jzlib
Merge pull request #17 from jglick/jrebel-memory

No need to maintain metaClasses map if JRebel integration is inactive.
doc improvements
[FIXED JENKINS-17713]

This is also reported as issue #19 and pull request #20. I claim this is
the correct fix.

Context: Ancestor.getRelativePath computes a wrong path in case the
current request path doesn't end with '/'.
[maven-release-plugin] prepare release stapler-parent-1.211