check-code: ban use of '[[ ]]' in tests

test-fileset: remove bashism, use test instead of '[[ ]]' Debian dash complains about it. $TESTTMP.sh: 213: $TESTTMP.sh: [[: not found

tests: test symbolic revision (de)reference in all hgweb styles Right now the way revisions get specified in hgweb urls is ignored, i.e. after revision is resolved, only its node hash (or sometimes local revision number) is used for all links in the templates. So, basically, every page for "tip" revision (or any other symbolic rev id) will dereference it: lose the nice symbolic name by putting node hash/local rev number in its place. The only exception so far is archive links on some pages: /archive/tip.{bz2,gz,zip}. The fact that this dereferencing is neither convenient nor intuitive is reflected in issue2296, issue2826 and issue3594. issue3634 also mentions this. But to fix this it's first needed to demonstrate and test the way templates currently form links. The new test file is separate from other hgweb tests, since it seems big and distinct enough. And it's so big because links are formed in each template independently, so it's necessary to test them all to avoid any inconsistent behavior.