Upgrade javaewah to version 0.7.9

Package was renamed, so I had to update the imports. Also, I verified
bitmap serialization was still compatible.

Change-Id: I161ad3875b963b56001beab477ef8d072accee4f

pom.xml

diff --git a/pom.xml b/pom.xml
index 72742c3..950b93e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -177,7 +177,7 @@
 
     <jgit-last-release-version>3.0.0.201306101825-r</jgit-last-release-version>
     <jsch-version>0.1.46</jsch-version>
-    <javaewah-version>0.5.6</javaewah-version>
+    <javaewah-version>0.7.9</javaewah-version>
     <junit-version>4.11</junit-version>
     <!-- TODO: update Maven dependency for args4j to 2.0.21 as soon as available on Maven Central -->
     <args4j-version>2.0.12</args4j-version>