Misc tweaks (#387)

HACKING.md

@@ -1,9 +1,10 @@
+ ## Compiler Gradle options
 
 There are several gradle flags one can use for Konan build.
 
 * **-Pkonanc_flags** passes flags to the compiler used to build stdlib
 
-        ./gradlew -Pkonanc_flags="-disable lower_inline -print_ir" stdlib
+        ./gradlew -Pkonanc_flags="--disable lower_inline --print_ir" stdlib
 
 * **-Pshims** compiles LLVM interface with tracing "shims". Allowing one 
     to trace the LLVM calls from the compiler.
@@ -15,6 +16,19 @@ There are several gradle flags one can use for Konan build.
 
         ./gradlew -Pfilter=overflowLong.kt run_external
 
-* **-Pperfix** allows one to choose external test directories to run. Only tests from directories with given prefix will be executed.
+* **-Pprefix** allows one to choose external test directories to run. Only tests from directories with given prefix will be executed.
 
-        ./gradlew -Pfilter=external_codegen_box_cast run_external
+        ./gradlew -Pprefix=external_codegen_box_cast run_external
+
+
+ ## Testing
+
+To run blackbox compiler tests from JVM Kotlin use (takes time):
+
+    ./gradlew run_external
+
+To update the blackbox compiler tests set TeamCity build number in `gradle.properties`:
+
+    testDataVersion=<build number>:id
+
+and run `./gradlew update_external_tests`