Updating readability and functionality

Here are my documented changes for each commit, listed by commit, for my branch.

First, Edited the format of the code to improve the readability.
[x] Removed the random space before each line
[x] Changed various locations where syntax was used differently than prior in the document.
[x] Converted all the bash style comments to multi/single line C/C++ style comments.
[x] Added block style comments for each method

Second, Updated the block style comments, fixed methods with 'couple' parameters.
[x] Added data types for each block comment parameter and updated the return types.
[x] Fixed the ticker functions 'couple' parameter, to set the default value correctly.

Third, Updated the API functions.
[x] Changed ticker function to call 'ticker' method via Cex.io API, which was not being implemented.
[x] Added order_book function, which correctly calls 'order_book' method via Cex.io API.

Fourth, Updated code.
[x] Changed PHP tag from short open tag, to reliable long tag.
[x] Updated place_order function, to have correct variables.

Fifth, Updated function comments.
[x] Updated the function parameter type of trade_history function.
[x] Updated the function parameter type of place_order function.

Sixth, Updated README.
[x] Edited formatting of PHP code examples.
[x] Fixed incorrect currency pairs in examples.
[x] Changed PHP short tag to long tag in examples.
[x] Fixed incorect PHP code examples.

Seventh, Updated code.
[x] Fixed the 'couple' variable in the api call for the 'place_order' function.