Implement single-level JSON parsing

add function parseSingleLevelJson, that parses JSON object, that doesn't contain nested objects or arrays, to map
Add tests, that check single level JSON parsing function
Fix coding style and typo

add spaces before keywords
rename singleLevelJSON_t to string_pair_t
fix typo in isValidUnquotedCharacter function name
replace == "" by .empty()
Move OAuth 1.0 sources to include/oauth and src/oauth folders
Fix indentation in ServiceConfiguration.h
Rename oauth folder to oauth1. Replace namespace OAuth with OAuth1

Move some files to the root of source and include folders.
Move OAuth 1.0 tests to test/oauth1 folder
Include missing header SingleLevelJSONTests.h
Fix JSON parsing

fix unicode character decoding
add comment about fitting unicode into char
Modify JSON parsing to throw exception for \uXXXX encoded characters

modify implementation
remove \uXXXX encoded character from test
Add ServiceConfiguration class for OAuth 2.0
Make ServiceConfiguration constructor to be private

Also move ServiceConfiguration header to src/oauth2 folder
Remove exception throwing in ServiceConfiguration methods
Add and partially implement OAuth 2.0 Service

add Service class
implement Service constructors and getAuthorizeUrl method
move ServiceConfiguration header to include
Add tests for getAuthorizeUrl method of OAuth 2.0 Service class
Add OAuth 2.0 Token class
Implement getAccessToken method, create stubs for getAccessToken* methods

implement getAccessToken method
create stubs for getAccessTokenAuthCodeGrant, getAccessTokenImplicitGrant, getAccessTokenOwnerCredentialsGrant, getAccessTokenClientCredentialsGrant
Implement OAuth 2.0 Service signRequest method
Add test for OAuth 2.0 Service signRequest method
Make buldable under gcc 4.8.1

exceptions after asserts added, otherwise complier was complaining about "control reaches end of non-void function"