ACCUMULO-3212 Do not load defaults into new Configuration objects for CredentialProvider

Formatter fixed up some non-complaint whitespace too.
Merge branch '1.6'

Conflicts:
	core/src/main/java/org/apache/accumulo/core/conf/SiteConfiguration.java
ACCUMULO-3213 Instead of trying to start 100 threads at once, do 16 at a time

Previously would have been about 50 add splits and 50 delete tables at a time,
this brings it back to 8 and 8, but leaves the same total number of requests
about equal.
Merge branch '1.6'
ACCUMULO-2913 Move timeout annotations to timeout rule with scaling
ACCUMULO-3217 Make KeyValue extend SimpleImmutableEntry instead of implement Map.Entry.

We get toString, hashCode and equals for free by extending SimpleImmutableEntry
over implementing Map.Entry. Without this change, users couldn't properly
use the Entry<Key,Value> objects that were returned by Scanners and BatchScanners.
Merge branch '1.5' into 1.6

Conflicts:
	server/tserver/src/main/java/org/apache/accumulo/tserver/Tablet.java
Merge branch '1.6'

Conflicts:
	core/src/main/java/org/apache/accumulo/core/data/Key.java
	core/src/main/java/org/apache/accumulo/core/data/KeyValue.java
	server/tserver/src/main/java/org/apache/accumulo/tserver/TabletServer.java
	server/tserver/src/main/java/org/apache/accumulo/tserver/tablet/Tablet.java
ACCUMULO-3215 Ensure that ImportTable writes absolute paths, not relative.

ImportExportIT creates a table, exports it and then imports it to the
same instance to ensure that the imported copy is equivalent
to the original. Without the changes to ImportTable, the test failed
because the copy was unusable due to incorrect metadata table entries.
Merge branch '1.6'

Conflicts:
	server/master/src/main/java/org/apache/accumulo/master/tableOps/ImportTable.java
ACCUMULO-3217 Fix use of deprecated members
Merge branch '1.6'
ACCUMULO-3220 Fail fast if the provided cipher isn't a block cipher.
Merge branch '1.6'
WIP