hg: recognize include and exclude patterns when cloning This commit teaches clone() to accept arguments defining file patterns to clone. This is the first step in teaching core code about the existence of a narrow clone. Right now, we only perform validation of the arguments and pass additional options into createopts to influence repository creation. Nothing of consequence happens with that creation option yet, however. For now, arbitrary restrictions exist, such as not allowing patterns for shared repos and disabling local copies when patterns are defined. We can potentially lift these restrictions in the future once partial clone/storage support is more flushed out. I figure it is best to reduce the surface area for bugs for the time being. It may seem weird to prefix these arguments with "store." However, clone is effectively pull + update and file patterns could apply to both the store and the working directory. The prefix is there to disambiguate in the future when this function may want to use different sets of patterns for the store and working directory. Differential Revision: https://phab.mercurial-scm.org/D4536