INSTALL,NOTES.ANDROID: minor updates.

Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6866)

INSTALL

@@ -145,8 +145,8 @@
                    put together one-size-fits-all instructions. You might
                    have to pass more flags or set up environment variables
                    to actually make it work. Android and iOS cases are
-                   discussed in corresponding Configurations/10-main.cf
-                   sections. But there are cases when this option alone is
+                   discussed in corresponding Configurations/15-*.conf
+                   files. But there are cases when this option alone is
                    sufficient. For example to build the mingw64 target on
                    Linux "--cross-compile-prefix=x86_64-w64-mingw32-"
                    works. Naturally provided that mingw packages are
@@ -157,10 +157,12 @@
                    "--cross-compile-prefix=mipsel-linux-gnu-" suffices
                    in such case. Needless to mention that you have to
                    invoke ./Configure, not ./config, and pass your target
-                   name explicitly.
+                   name explicitly. Also, note that --openssldir refers
+                   to target's file system, not one you are building on.
 
   --debug
-                   Build OpenSSL with debugging symbols.
+                   Build OpenSSL with debugging symbols and zero optimization
+                   level.
 
   --libdir=DIR
                    The name of the directory under the top of the installation

NOTES.ANDROID

@@ -46,8 +46,8 @@
  One can engage clang by adjusting PATH to cover NDK's clang. Just keep
  in mind that if you miss it, Configure will try to use gcc... Also,
  PATH would need even further adjustment to cover unprefixed, yet
- target-specific, ar and ranlib (or not, if you use binutils-multiarch
- on your Linux).
+ target-specific, ar and ranlib. It's possible that you don't need to
+ bother, if binutils-multiarch is installed on your Linux system.
 
  Running tests (on Linux)
  ------------------------