Merge branch 'reactivex--add-as-dependency' into 'master'

Add ReactiveX (rxjava + rxandroid) as dependency

This is going to be used to make the managing of async tasks in F-Droid easier to reason about. It does this by using a more functional style to performing multiple different asynchronous tasks as compared to the Android `AsyncTask` or `Service` or some other approach.

More specifically, I have some changes coming that will use this dependency.
I wanted to merge this separately so that it doesn't matter which of the changes I'm working on gets merged first.

I've never added a `dependencyVerification` to the gradle build before, and there wasn't a whole bunch of docs on the interwebs about how to do that. So I did a SHA256 sum of some other .jar files in my gradle cache and compared them to the existing dependency verification settings and they did match. So I also did a SHA256 sum of the newly added dependencies and gradle seems happy with the hashes I've chosen.

See merge request !197

F-Droid/build.gradle

@@ -22,6 +22,8 @@ dependencies {
     compile('ch.acra:acra:4.8.0') {
         exclude module: 'support-v4'
     }
+    compile 'io.reactivex:rxjava:1.1.0'
+    compile 'io.reactivex:rxandroid:0.23.0'
 
     androidTestCompile 'commons-io:commons-io:2.2'
 }
@@ -73,6 +75,8 @@ if (!hasProperty('sourceDeps')) {
             'com.madgag.spongycastle:prov:029f26cd6b67c06ffa05702d426d472c141789001bcb15b7262ed86c868e5643',
             'com.madgag.spongycastle:core:9b6b7ac856b91bcda2ede694eccd26cefb0bf0b09b89f13cda05b5da5ff68c6b',
             'ch.acra:acra:d8ef3b76760e3faf7fe0ea0231fbe98e57f8f06ed3b86c877e6aa95bbc188aac',
+            'io.reactivex:rxjava:2c162afd78eba217cdfee78b60e85d3bfb667db61e12bc95e3cf2ddc5beeadf6',
+            'io.reactivex:rxandroid:35c1a90f8c1f499db3c1f3d608e1f191ac8afddb10c02dd91ef04c03a0a4bcda',
         ]
     }
 

F-Droid/proguard-rules.pro

@@ -33,3 +33,10 @@
 -keep public class * extends android.support.v4.view.ActionProvider {
     public <init>(android.content.Context);
 }
+
+# The rxjava library depends on sun.misc.Unsafe, which is unavailable on Android
+# The rxjava team is aware of this, and mention in the docs that they only use
+# the unsafe functionality if the platform supports it.
+#  - https://github.com/ReactiveX/RxJava/issues/1415#issuecomment-48390883
+#  - https://github.com/ReactiveX/RxJava/blob/1.x/src/main/java/rx/internal/util/unsafe/UnsafeAccess.java#L23
+-dontwarn rx.internal.util.**