Standardize builders docstrings and remove '\'

Standardize the docstrings as much as possible in the builders module to
provide good working examples to be followed. Remove unnecessary use of
'\' to reduce copy 'n' paste and convert last remaining inline example
to unit test and include inline into docstring.

Change-Id: I02fe217f3a122aaac4d770e638011144236285cb

tests/yamlparser/fixtures/critical_block_complete001.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8"?>
+<project>
+  <actions/>
+  <description>&lt;!-- Managed by Jenkins Job Builder --&gt;</description>
+  <keepDependencies>false</keepDependencies>
+  <blockBuildWhenDownstreamBuilding>false</blockBuildWhenDownstreamBuilding>
+  <blockBuildWhenUpstreamBuilding>false</blockBuildWhenUpstreamBuilding>
+  <concurrentBuild>false</concurrentBuild>
+  <canRoam>true</canRoam>
+  <properties/>
+  <scm class="hudson.scm.NullSCM"/>
+  <builders>
+    <org.jvnet.hudson.plugins.exclusion.CriticalBlockStart plugin="Exclusion"/>
+    <hudson.tasks.Shell>
+      <command>rollback-my-data-base</command>
+    </hudson.tasks.Shell>
+    <org.jvnet.hudson.plugins.exclusion.CriticalBlockEnd plugin="Exclusion"/>
+  </builders>
+  <publishers/>
+  <buildWrappers>
+    <org.jvnet.hudson.plugins.exclusion.IdAllocator plugin="Exclusion">
+      <ids>
+        <org.jvnet.hudson.plugins.exclusion.DefaultIdType>
+          <name>MYRESOURCE1</name>
+        </org.jvnet.hudson.plugins.exclusion.DefaultIdType>
+      </ids>
+    </org.jvnet.hudson.plugins.exclusion.IdAllocator>
+  </buildWrappers>
+</project>

tests/yamlparser/fixtures/critical_block_complete001.yaml

@@ -0,0 +1,18 @@
+- wrapper:
+    name: critical-block-exclusion
+    wrappers:
+      - exclusion:
+          resources:
+            - myresource1
+
+- job:
+    name: critical-block-example
+    project-type: freestyle
+    wrappers:
+      - critical-block-exclusion
+    builders:
+      - critical-block-start
+      - shell:
+          #!/bin/bash -ex
+          rollback-my-data-base
+      - critical-block-end