Create lookup package
rename Definition to PainlessLookup and move to lookup package
rename Definition.Method to PainlessMethod
rename Definition.MethodKey to PainlessMethod
rename Definition.Field to PainlessField
rename Definition.Struct to PainlessClass
rename Definition.Cast to PainlessCast
rename Whitelist.Struct to WhitelistClass
rename Whitelist.Constructor to WhitelistConstructor
rename Whitelist.Method to WhitelistMethod
rename Whitelist.Field to WhitelistField
In order to build a plugin that extends the painless whitelist, the spi
classes must be available to the plugin at compile time. This commit
moves the spi classes into a separate jar which will be published. Any
plugin authors whiching to extend painless through spi would then add a
compileOnly dependency on this jar.