I started working on #465 and made some corresponding std.io
API changes.
New structs:
* std.io.FileInStream
* std.io.FileOutStream
* std.io.BufferedOutStream
* std.io.BufferedInStream
Removed:
* std.io.File.in_stream
* std.io.File.out_stream
Now instead of &file.out_stream or &file.in_stream to get access to
the stream API for a file, you get it like this:
var file_in_stream = io.FileInStream.init(&file);
const in_stream = &file_in_stream.stream;
var file_out_stream = io.FileOutStream.init(&file);
const out_stream = &file_out_stream.stream;
This is evidence that we might not need any OOP features -
See #130.
* Merge io.InStream and io.OutStream into io.File
* Introduce io.OutStream and io.InStream interfaces
- io.File implements both of these
* Move mem.IncrementingAllocator to heap.IncrementingAllocator
Instead of:
```
%return std.io.stderr.printf("hello\n");
```
now do:
```
std.debug.warn("hello\n");
```
To print to stdout, see `io.getStdOut()`.
* Rename std.ArrayList.resizeDown to std.ArrayList.shrink.
