rewriteutil: use precheck() in uncommit and amend commands Differential Revision: https://phab.mercurial-scm.org/D1526

rewriteutil: add a precheck function to check if revs can be rewritten The precheck function is intended to be used before we start rewritting changesets. Differential Revision: https://phab.mercurial-scm.org/D1503

rewriteutil: add utility function to check if we can create new unstable cset This patch adds a new file which will contain utility functions related to rewritting changesets. It also adds a utility function to check if the rewritting operation creates new unstable changesets and are we allowed to create them. This rewriteutil.py introduced in this patch and the utility functions added in the upcoming patches exists in the evolve extension are being ported from there. Differential Revision: https://phab.mercurial-scm.org/D1502

test-run-tests: do not rebuild hg in the test d600bda4 and fc0f3ed0 added code to call `$PYTHON run-tests.py ...`. That will rebuild hg, is slow and could have other crashes from setup.py, like: Unable to find a working hg binary to extract the version from the repository tags Therefore use `run-tests.py -l` instead. Differential Revision: https://phab.mercurial-scm.org/D1595

remotenames: consider existing data while storing newer data Previously reviewed as D1357. Differential Revision: https://phab.mercurial-scm.org/D1551

remotenames: add functions to read remotenames data from .hg/remotenames/ This patch functions which can be used to read remotenames data from .hg/remotenames/. The logic for the function which reads the remotenames file is taken from the remotenames extension. Previously reviewed as D940. Differential Revision: https://phab.mercurial-scm.org/D1550

remotenames: add test showing overwriting on remotenames data The current storage logic every time overwrites the existing data with the new data. This patch adds test to demonstrate that. To fix this, we need to add logic to read existing remotenames data and merge with existing data which will be added in upcoming changesets. Previously reviewed as D1356. Differential Revision: https://phab.mercurial-scm.org/D1549

remotenames: add functionality to store remotenames under .hg/hgremotenames/ This patch moves the functionality from remotenames extension to store remotenames to core. Storage format used by remotenames extension: A single file `.hg/remotenames` with an entry in each line where each line is of format: `node nametype remotepath/name` where nametype is either 'bookmarks' or 'branches'. This was not the best way to store data, so while moving to core the storage format was changed but yet not the final format. The storage format used by core after this patch will be: * A file for each type of name i.e. bookmarks and branches in .hg/remotenames/ directory * A version number on the top of the file. The version for current format is 0. * An entry in each line where each line is of the format `node\0remotepath\0name` The logic to sync with existing remotenames file and saving journals and other related things will be moved to core in next patches incrementally. Thanks to Ryan, Augie and Durham for suggestions on storage format. Previously reviewed as D939. Differential Revision: https://phab.mercurial-scm.org/D1548