Removes hardcoded extension of PNG to allow OEM versions (qmg)

- adds unit-tests via two qmg files (one 9 patch, one regular)

CHANGES

@@ -47,6 +47,7 @@ v2.0.0 (TBA)
 -Fixed (issue #682) - Fixed handling renamed manifests with ("yi")
 -Fixed (issue #664) - Fixed issue with apks with large StringPools failing to decode.
 -Fixed (issue #447) - Fixed bad cast of ResStringValue to ResAtr by handling ResStringValue correctly (Thanks whydoubt)
+-Fixed (issue #689) - Fixed issue with hard coding extension as PNG.
 -Fixed issue with APKs with multiple dex files.
 -Fixed issue with using Apktool without smali/baksmali for ApktoolProperties (Thanks teprrr)
 -Fixed issue with non-URI standard characters in apk name (Thanks rover12421)

brut.apktool/apktool-lib/src/main/java/brut/androlib/res/decoder/ResFileDecoder.java

@@ -61,11 +61,11 @@ public class ResFileDecoder {
                 return;
             }
             if (typeName.equals("drawable") || typeName.equals("mipmap")) {
-                if (inFileName.toLowerCase().endsWith(".9.png")) {
+                if (inFileName.toLowerCase().endsWith(".9." + ext)) {
                     outFileName = outResName + ".9" + ext;
 
                     // check for htc .r.9.png
-                    if (inFileName.toLowerCase().endsWith(".r.9.png")) {
+                    if (inFileName.toLowerCase().endsWith(".r.9" + ext)) {
                         outFileName = outResName + ".r.9" + ext;
                     }