#11716 reports multiple git blame processes hanging around
this was thought to be due to timeouts, however on closer look this
appears to be due to the Close() function of the BlameReader hanging
with a blocked stdout pipe.

This PR fixes this Close function to:

* Cancel the context of the cmd
* Close the StdoutReader - ensuring that the output pipe is closed

Further it makes the context of the `git blame` command a child of the
request context - ensuring that even if Close() is not called, on
cancellation of the Request the blame is command will also be cancelled.

Fixes #11716
Closes #11727

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Server-side syntax hilighting for all code

This PR does a few things:

* Remove all traces of highlight.js
* Use chroma library to provide fast syntax hilighting directly on the server
* Provide syntax hilighting for diffs
* Re-style both unified and split diffs views
* Add custom syntax hilighting styling for both regular and arc-green

Fixes #7729
Fixes #10157
Fixes #11825
Fixes #7728
Fixes #3872
Fixes #3682

And perhaps gets closer to #9553

* fix line marker

* fix repo search

* Fix single line select

* properly load settings

* npm uninstall highlight.js

* review suggestion

* code review

* forgot to call function

* fix test

* Apply suggestions from code review

suggestions from @silverwind thanks

Co-authored-by: silverwind <me@silverwind.io>

* code review

* copy/paste error

* Use const for highlight size limit

* Update web_src/less/_repository.less

Co-authored-by: Lauris BH <lauris@nix.lv>

* update size limit to 1MB and other styling tweaks

* fix highlighting for certain diff sections

* fix test

* add worker back as suggested

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Lauris BH <lauris@nix.lv>

* Rework blame template and styling

* cleanup template and add missing NumLines

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

Fix #11280

speed up page generation by making avatar lookup occur at the browser
not at page generation

* Protect against evil email address ".."

* hash the complete email address

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-Authored-By: Lauris BH <lauris@nix.lv>

* update #8687 respect file locking

* upate #8687 Add LFS locker information

* update #8719 enhance coding style and return error

* display ui time with customize time location

* fix lint

* rename UILocation to DefaultUILocation

* move time related functions to modules/timeutil

* fix tests

* fix tests

* fix build

* fix swagger

* monitor all git commands; move blame to git package and replace git as a variable

* use git command but not other commands

* fix build

* move exec.Command to git.NewCommand

* fix fmt

* remove unrelated changes

* remove unrelated changes

* refactor IsEmpty and add tests

* fix tests

* fix tests

* fix tests

* fix tests

* remove gitLogger

* fix fmt

* fix isEmpty

* fix lint

* fix tests