Added current values

[tagyro]

Added $APP_ORIGINAL_VERSION and $APP_ORIGINAL_BUILD

[tagyro]

The idea behind adding these two variables is to (maybe) use them in an "auto-increment" way, something like:
$APP_VERSION = $APP_ORIGINAL_VERSION + 1 or
$APP_BUILD = $APP_ORIGINAL_BUILD + 1
Does that make sense?

[KirillAshikhmin]

@tagyro This approach will not work for the auto-increment the version number.
For each run the older version will be the same.
In order to increment the version recommend using $ BITRISE_BUILD_NUMBER