Some beginning work on squashfs.Writer

Just laying out some of the functions and what they do.

writer.go

@@ -0,0 +1,56 @@
+package squashfs
+
+import (
+	"errors"
+	"os"
+
+	"github.com/CalebQ42/squashfs/internal/inode"
+)
+
+//Writer is an interface to write a squashfs. Doesn't write until you call Write (TODO: maybe not do Write...)
+type Writer struct {
+	files       map[string]*File
+	directories []string
+}
+
+func convertFile(file *os.File) (*File, error) {
+	stat, err := file.Stat()
+	if err != nil {
+		return nil, err
+	}
+	var filType int
+	if stat.IsDir() {
+		//TODO
+	} else if stat.Mode().IsRegular() {
+		filType = inode.BasicFileType
+		return &File{
+			Reader:  file,
+			name:    file.Name(),
+			filType: filType,
+		}, nil
+	} else if stat.Mode()&os.ModeSymlink == os.ModeSymlink {
+		//TODO: implement symlink support
+		return nil, errors.New("No symlink support. No support at all actually...")
+	}
+	return nil, errors.New("File type is NOT supported")
+}
+
+//AddFilesToPath adds the give os.Files to the given path within the squashfs archive.
+func (w *Writer) AddFilesToPath(squashfsPath string, files ...*os.File) error {
+	//TODO
+	return errors.New("Don't")
+}
+
+//AddFiles adds all files given to the root directory
+func (w *Writer) AddFiles(files ...*os.File) error {
+	//TODO
+	return errors.New("Don't")
+}
+
+//RemoveFileAt removes the file at filepath from the Writer.
+//If multiple files match the given filepath (such as if there are wildcards), all matching files are removed.
+//If one or more files are removed, returns true.
+func (w *Writer) RemoveFileAt(filepath string) bool {
+	//TODO
+	return false
+}