Get rid of the with-static.sh script

CGO can perform variable substitution in the directives, so we don't
need to use a script to set up the variables; we can let the go tool do
it for us.
diff --git a/Makefile b/Makefile
index 3040857..39fc558 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@
 
 test: build-libgit2
 	go run script/check-MakeGitError-thread-lock.go
-	./script/with-static.sh go test ./...
+	go test ./...
 
 install: build-libgit2
-	./script/with-static.sh go install ./...
+	go install ./...
diff --git a/README.md b/README.md
index 315032f..bd918d6 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@
 
     import "github.com/libgit2/git2go"
 
-to use the version which works against the latest release.
+to use the 'master' branch, which works against the latest release of libgit2, whichever that one is at the time.
 
 ### From `next`
 
@@ -44,15 +44,14 @@
 Running the tests
 -----------------
 
-For the stable version, `go test` will work as usual. For the `next` branch, similarly to installing, running the tests requires linking against the local libgit2 library, so the Makefile provides a wrapper
+For the stable version, `go test` will work as usual. For the `next` branch, similarly to installing, running the tests requires building a local libgit2 library, so the Makefile provides a wrapper that makes sure it's built
 
     make test
 
-Alternatively, if you want to pass arguments to `go test`, you can use the script that sets it all up
+Alternatively, you can build the library manually first and then run the tests
 
-    ./script/with-static.sh go test -v
-
-which will run the specified arguments with the correct environment variables.
+    ./script/build-libgit2-static.sh
+    go test -v
 
 License
 -------
diff --git a/git.go b/git.go
index 53b1a12..77394cf 100644
--- a/git.go
+++ b/git.go
@@ -1,6 +1,10 @@
 package git
 
 /*
+#cgo CFLAGS: -I${SRCDIR}/vendor/libgit2/include
+#cgo LDFLAGS: -L${SRCDIR}/vendor/libgit2/build/ -lgit2
+#cgo windows LDFLAGS: -lwinhttp
+#cgo !windows pkg-config: --static ${SRCDIR}/vendor/libgit2/build/libgit2.pc
 #include <git2.h>
 #include <git2/sys/openssl.h>
 
diff --git a/script/with-static.sh b/script/with-static.sh
deleted file mode 100755
index 3f60e31..0000000
--- a/script/with-static.sh
+++ /dev/null
@@ -1,12 +0,0 @@
-#!/bin/sh
-
-set -ex
-
-export BUILD="$PWD/vendor/libgit2/build"
-export PCFILE="$BUILD/libgit2.pc"
-
-FLAGS=$(pkg-config --static --libs $PCFILE) || exit 1
-export CGO_LDFLAGS="$BUILD/libgit2.a -L$BUILD ${FLAGS}"
-export CGO_CFLAGS="-I$PWD/vendor/libgit2/include"
-
-$@