doc: use double quotation mark to quote arguments in examples for Windows users

On Windows, only double quotation mark can quote command line
arguments.

So, this patch uses double quotation mark to quote command line
arguments in all examples of online help document.

hgext/churn.py

@@ -103,16 +103,16 b' def churn(ui, repo, *pats, **opts):'
     Examples::
 
       # display count of changed lines for every committer
-      hg churn -t '{author|email}'
+      hg churn -t "{author|email}"
 
       # display daily activity graph
-      hg churn -f '%H' -s -c
+      hg churn -f "%H" -s -c
 
       # display activity of developers by month
-      hg churn -f '%Y-%m' -s -c
+      hg churn -f "%Y-%m" -s -c
 
       # display count of lines changed in every year
-      hg churn -f '%Y' -s
+      hg churn -f "%Y" -s
 
     It is possible to map alternate email addresses to a main address
     by providing a file using the following format::

mercurial/commands.py

@@ -556,7 +556,7 b' def bisect(ui, repo, rev=None, extra=Non'
 
       - skip all revisions that do not touch directories ``foo`` or ``bar``::
 
-          hg bisect --skip '!( file("path:foo") & file("path:bar") )'
+          hg bisect --skip "!( file('path:foo') & file('path:bar') )"
 
       - forget the current bisection::
 
@@ -568,7 +568,7 b' def bisect(ui, repo, rev=None, extra=Non'
           hg bisect --reset
           hg bisect --bad 34
           hg bisect --good 12
-          hg bisect --command 'make && make tests'
+          hg bisect --command "make && make tests"
 
       - see all changesets whose states are already known in the current
         bisection::

mercurial/help/phases.txt

@@ -79,6 +79,6 b' Examples'
 
  - resynchronize draft changesets relative to a remote repository::
 
-     hg phase -fd 'outgoing(URL)'
+     hg phase -fd "outgoing(URL)"
 
 See :hg:`help phase` for more information on manually manipulating phases.