rhg: Remove `rhg.fallback-executable=hg` default configuration
When `rhg.on-unsupported` is configured to `fallback` and an unsupported
feature is encountered, the previous default was to look for an `hg`
executable in `$PATH`.
This default was fragile since it was easy to end up accidentally using
an older version of Mercurial installed system-wide,
when a local (perhaps patched) installation was intended.
Instead, it is now an error to have `rhg.on-unsupported=fallback`
without also configuring an explicit path or the fallback executable.
Differential Revision: https://phab.mercurial-scm.org/D10189
{
// 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)
}