psr2 fixes
added more code examples
normalized input values of brightness and contrast filters
Rewrite resize function. Fixes #1

The resize function is now extended so it supports more functionality. Parameter passing with arrays has been removed.

New functionality included:
- Resizing of a single image side
- Preserve image ratio when both width and height have been set (treated as maximum values)
- Prevent image from being upsized

Signed-off-by: Dries Vints <dries.vints@gmail.com>
Fix old unit tests

Signed-off-by: Dries Vints <dries.vints@gmail.com>
New unit tests for new resize function

Signed-off-by: Dries Vints <dries.vints@gmail.com>
Merge pull request #2 from driesvints/dv/extend-resize-function

Extend resize function. Fixes #1
added more tests for new resize method
updated readme on new resize method
added legacy resizing method
psr fixes
removed array param in grab method
added method documentation
textual improvments of the documentation
code formatting
added option to reset an "empty" image
Update src/Intervention/Image/Image.php

Added crop function: Image::crop($src_x , $src_y , $src_w , $src_h)
Update src/Intervention/Image/Image.php

Added return object Image for chaining
added crop method
readme edit