Auto merge of rust-lang#2842 - alx741:update_manpages, r=alexcrichton

Update manpages with new flags

Add the [new flags](http://blog.rust-lang.org/2016/07/07/Rust-1.10.html)

src/etc/man/cargo-install.1

@@ -98,6 +98,11 @@ Space\-separated list of features to activate.
 .RS
 .RE
 .TP
+.B \-f, \-\-force
+Force overwriting existing crates or binaries
+.RS
+.RE
+.TP
 .B \-\-no\-default\-features
 Do not build the \f[C]default\f[] feature.
 .RS

src/etc/man/cargo-test.1

@@ -57,6 +57,11 @@ Test only this package\[aq]s library.
 .RS
 .RE
 .TP
+.B \-\-doc
+Test only this library\[aq]s documentation
+.RS
+.RE
+.TP
 .B \-\-bin \f[I]NAME\f[]
 Test only the specified binary.
 .RS

src/etc/man/cargo.1

@@ -27,6 +27,11 @@ List all available cargo commands.
 .RS
 .RE
 .TP
+.B \-\-explain CODE
+Run \f[C]rustc\ \-\-explain\ CODE\f[]
+.RS
+.RE
+.TP
 .B \-v, \-\-verbose
 Use verbose output.
 .RS