#KT-44815 Fixed

Split import handlers into multiple files
Add empty Maven handler for Android Studio

Add testRuntime dependency on kx-serialization-plugin for all modules which require compiler
plugins in test classpath

Env variable for idea SDK on TeamCity
Fix kotlin_root dir relative path

Updated broken API after rebase to 1.1.50

Bintray upload setup

IntelliJ project, ant task and maven goal for serialization plugin
Serialization IDEA plugin

- Actualize build requirements and steps
- Extract Gradle plugin readme to the corresponding folder
- Rewrite Libraries and Maven Tools readme

#KT-20995 Fixed

The idea is to keep all declarations in the same packages from Kotlin's
point of view, but use JvmPackageName annotation to move them to another
JVM package, to avoid the split package problem which is otherwise
unsolvable when using module path on Java 9 (KT-19258).

In this commit, kotlin-stdlib-jre7/8 are moved to kotlin-stdlib-jdk7/8
and in the subsequent commit, -jre7/8 are restored. This is done in
order to make Git recognize this as a file move to preserve history.

Include new stdlib-jdkN artifacts in manifest version tests.

Also update links and overall readme structure.