tools.which: adding some docs and cleanup.
tools.which: cleanup code a little.
X11 XK_ISO_Left_Tab is shift tab
X11, give same input as gtk when pressing shift, tab, alt..
ui.backend.cocoa.views: fix build error on older OSX versions.
ui.backend.cocoa.views: add platforms.txt.
factor.sh: Allow bootstrap on other branches for commands that don't pull from git.
io.streams.peek: Implement peek and peek1.
io.streams.peek: use namespaces.
compiler.tree.propagation.known-words: adding known outputs for some words.
Revert "compiler.tree.propagation.known-words: adding known outputs for some words."

This reverts commit 16d8e6555b9f82ec55bbb9f9e57ad638bae04b7c.
compiler.tree.propagation.known-words: retry this change, some issue with use vocabs.
math.functions: adding "round-to".
twitter: Update API url.