stringutil: teach pprint() to indent
This will make data structure dumping in various places a bit
easier to read and diff. Since I wanted this for `hg debugwireproto`
output, I added indentation to it.
A more advanced pretty printer implementation would conditionally
add newlines if output is too long. But it is vastly simpler to
be consistent and always add newlines when indenting.
Again, I'm not crazy about the verbosity of the code and there is
room to consolidate logic for "print a collection." But this isn't
the most complicated code in the world and I'm not convinced it is
worth doing.
Differential Revision: https://phab.mercurial-scm.org/D4399
{
// 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)
}