Depend on 0.13 Android binaries from custom JCenter repo

Only needed until artifacts propagate through Maven Central.

[cli] spawn xterm on linux to run the packager

Also use ANDROID_HOME env var when running adb.

Temporarily depend on 0.12 Android binaries from JCenter repo

Published version 0.12.0 of the Android binaries. Naming the
version 0.12.0-SNAPSHOT or 0.12.0-rc is not supported,
will come up with a better version scheme for next release.

The version has been published to Maven Central:
https://repo1.maven.org/maven2/com/facebook/react/react-native/

However, after more than an hour it's still not available and
Gradle won't fetch it because it hasn't been mirrored to JCenter:
http://search.maven.org/#search%7Cga%7C1%7Ca%3A%22react-native%22
https://bintray.com/bintray/jcenter/com.facebook.react%3Areact-native/view

As a workaround to make it available now, I published it under my
account which makes it available immediately:
https://bintray.com/mkonicek/maven/react-native/view

I also submitted a request to Bintray to publish the binaries here:
https://bintray.com/bintray/jcenter/com.facebook.react%3Areact-native/view

Once 0.12.0 propagates, we can revert this commit.

None of this affects the npm versioning. The npm version is 0.12.0-rc.

[0.11.0]

0.11.0-rc

[0.10.0] Release 0.10.0

0.10.0-rc

0.9.0: Set package.json and podspec versions

Update version in React.podspec and package.json

Bump to 0.8.0