facebook service returns 100 posts
created vk service and class for api requests
added getUserById and getGroupById methods
getPosts returns a common-structured array
getPosts returns a common-structured array
fb getposts gets comments and likes count. getposts now uses a single request to get necessary fields
Merge branch 'twitter'
Merge branch 'vk'
response structures results from social networks into named sub-arrays
deleted unnecessary commented code
added phpdoc