samples: Add scripts for samples building

This pach adds a root gradle project in the samples directory
which allows one to build all gradle samples using `./gradlew build`
command. It also adds a shell script in the samples directory which
can build all samples (excluding tensorflow one) using their build.sh
scripts.

samples/libcurl/build.gradle

@@ -1,16 +1,3 @@
-buildscript {
-    repositories {
-        mavenCentral()
-        maven {
-            url  "https://dl.bintray.com/jetbrains/kotlin-native-dependencies"
-        }
-    }
-
-    dependencies {
-        classpath "org.jetbrains.kotlin:kotlin-native-gradle-plugin:+"
-    }
-}
-
 apply plugin: 'konan'
 
 konanInterop {
@@ -28,12 +15,18 @@ konanArtifacts {
     }
 }
 
-
 build {
+    project.ext { outputFile = "${projectDir.canonicalPath}/${file(compileKonanCurl.artifactPath).name}" }
     doLast {
         copy {
             from compileKonanCurl.artifactPath
             into projectDir.canonicalPath
         }
     }
+}
+
+clean {
+    doLast {
+        delete outputFile
+    }
 }

samples/libcurl/gradle.properties

@@ -1 +0,0 @@
-konan.home=../../dist

samples/libcurl/gradle.properties.for_bundle

@@ -1 +0,0 @@
-konan.home=../..