code cleanup, fix for ReplaceInputStream
- [DBH] src/be/nikiroo/utils/Cache.java
- [DBH] src/be/nikiroo/utils/IOUtils.java
- [DBH] src/be/nikiroo/utils/Image.java
- [DBH] src/be/nikiroo/utils/streams/Base64.java
- [DBH] src/be/nikiroo/utils/streams/Base64InputStream.java
- [DBH] src/be/nikiroo/utils/streams/BufferedInputStream.java
- [DBH] src/be/nikiroo/utils/streams/MarkableFileInputStream.java
- [DBH] src/be/nikiroo/utils/streams/NextableInputStream.java
- [DBH] src/be/nikiroo/utils/streams/ReplaceInputStream.java
- [DBH] src/be/nikiroo/utils/streams/ReplaceOutputStream.java