Fix support for installing node on SmartOS

uname on SmartOS cannot be used to guess if 32 and/or 64 bits binaries
are supported, and its output is different than other uname commands on
other operating systems.

This change uses pkg_info to determine what types of binaries pkgsrc
would install. If pkg_info fails to run or is not present, this change
falls back to using isainfo -n, which determines what the kernel
supports.

It allows users to install node binaries on Solaris derivatives. io.js
can also be installed on Solaris derivatives starting with version
v3.3.1.

test/mocks/isainfo_amd64

@@ -0,0 +1,5 @@
+if [ "_$1" = "_-n" ]; then
+  echo "amd64"
+else
+  echo "amd64 i386"
+fi

test/mocks/isainfo_x86

@@ -0,0 +1,5 @@
+if [ "_$1" = "_-n" ]; then
+  echo "i386"
+else
+  echo "i386"
+fi

test/mocks/pkg_info_amd64

@@ -0,0 +1 @@
+echo "x86_64"

test/mocks/pkg_info_x86

@@ -0,0 +1 @@
+echo "i386"

test/mocks/uname_osx_amd64

@@ -0,0 +1,5 @@
+if [ "_$1" = "_-m" ]; then
+  echo "x86_64"
+else
+  echo "Darwin foo.local 13.4.0 Darwin Kernel Version 13.4.0: Sun Aug 17 19:50:11 PDT 2014; root:xnu-2422.115.4~1/RELEASE_X86_64 x86_64"
+ fi

test/mocks/uname_osx_x86

@@ -0,0 +1,5 @@
+if [ "_$1" = "_-m" ]; then
+  echo "i386"
+else
+  echo "Darwin foo.local 13.4.0 Darwin Kernel Version 13.4.0: Sun Aug 17 19:50:11 PDT 2014; root:xnu-2422.115.4~1/RELEASE_I386 i386"
+ fi

test/mocks/uname_smartos_amd64

@@ -0,0 +1,5 @@
+if [ "_$1" = "_-m" ]; then
+  echo "i86pc"
+else
+  echo "SunOS dev 5.11 joyent_20150219T102159Z i86pc i386 i86pc Solaris"
+fi

test/mocks/uname_smartos_x86

@@ -0,0 +1,5 @@
+if [ "_$1" = "_-m" ]; then
+  echo "i86pc"
+else
+  echo "SunOS dev 5.11 joyent_20150219T102159Z i86pc i386 i86pc Solaris"
+fi