Fixed require paths

Previously, relative require paths would be resolved based on the
current working directory. They are now resolved based on the path
of the module.

parser/meta.go

@@ -1,14 +1,11 @@
 package parser
 
-import "os"
 import "path/filepath"
 import "git.tebibyte.media/arf/arf/lexer"
 import "git.tebibyte.media/arf/arf/infoerr"
 
 // parseMeta parsese the metadata header at the top of an arf file.
 func (parser *parsingOperation) parseMeta () (err error) {
-	cwd, _ := os.Getwd()
-	
 	for {
 		err = parser.expect (
 			lexer.TokenKindName,
@@ -37,7 +34,7 @@ func (parser *parsingOperation) parseMeta () (err error) {
 		case "require":
 			// if import path is relative, get absolute path.
 			if value[0] == '.' {
-				value = filepath.Join(cwd, value)
+				value = filepath.Join(parser.modulePath, value)
 			} else if value[0] != '/' {
 				// TODO: get arf import path from an env
 				// variable, and default to this if not found.