.jshintrc

merge: use operation-provided labels (ex: dest/source) in several merge-tools

Tools that did not use labels already, used only one, or used some label other
than the exact strings of "local" or "other" were unmodified.  Cases that used
the label "base" were modified as well, if they were otherwise changed in this
CL; "merged" was *not* changed.

There are other possible changes we might want to make, but I didn't:
- bcompare (linux and osx) uses the labels "parent1" and "parent2" instead of
  "local" and "other", so it was left alone, even though beyondcompare3
  (windows) *was* changed.
- araxis used the labels "Other", "Base", and "Local :$local", so it was also
  left alone.
- UltraCompare didn't provide a label for 'local', just for 'base' and 'other',
  so it was left alone.

Differential Revision: https://phab.mercurial-scm.org/D2012

{
    // Enforcing
    "eqeqeq"        : true,     // true: Require triple equals (===) for comparison
    "forin"         : true,     // true: Require filtering for..in loops with obj.hasOwnProperty()
    "freeze"        : true,     // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
    "nonbsp"        : true,     // true: Prohibit "non-breaking whitespace" characters.
    "undef"         : true,     // true: Require all non-global variables to be declared (prevents global leaks)

    // Environments
    "browser"       : true      // Web Browser (window, document, etc)
}