Update build config, gitignore after testing

.gitignore

@@ -1,22 +1,13 @@
 # Android specific
-bin
-gen
-obj
-libs/armeabi
 lint.xml
 local.properties
 release.properties
-ant.properties
 *.class
 *.apk
 
 # Gradle
 .gradle
 build
-gradle.properties
-# this is in here because the prepare-tests thing modifies it, and we DON'T
-# want this to be commited.  use git add -f to work on this file.
-settings.gradle
 
 # Maven
 target

OpenKeychain/build.gradle

@@ -268,10 +268,11 @@ android {
 
     dexOptions {
         incremental = true
-        // Disable preDexing, causes com.android.dx.cf.iface.ParseException: bad class file magic (cafebabe) or version (0034.0000) on some systems
+        preDexLibraries = true
-        preDexLibraries = false
+        // dexInProcess requires much RAM, which is not available on all dev systems
+        dexInProcess = false
         jumboMode = true
-        javaMaxHeapSize "2g"
+        javaMaxHeapSize "4g"
     }
 
     packagingOptions {
@@ -285,8 +286,6 @@ android {
     }
 }
 
-// apply plugin: 'spoon'
-
 task jacocoTestReport(type:JacocoReport, dependsOn: "testFdroidDebugUnitTest") {
     group = "Reporting"
     description = "Generate Jacoco coverage reports"