It would be useful to allow "gradle src" or "gradle javadoc" to work without needing the "-PBUILD_JAVADOC=true" or "-DBUILD_SRC_ZIP=true" flag, respectively.

Currently the "sdk" task unconditionally depends on the "javadoc" and "src" tasks. Those tasks are only enabled if the corresponding flag is set. If instead we changed the script such that the "javadoc" and "src" tasks were always enabled, but only added as dependencies of the "sdk" task when the corresponding flag is set, a user would be able to say "gradle javadoc" and it would do the expected thing.