Adding more parameters to services

Monit's xml contains more parameters than we already support, it would
be nice if we can support more info about system and services.

New parameters:

 * System:
   * os: Operating system
   * osversion: Operating system version
   * arch: Machine architecture
   * cputotal: Total nr. of CPUs
   * memtotal: Total size of memory (in KB) 
   * swaptotal: Total size of swap area (in KB, nil if not supported)
 * Filesystem:
   * inode_percent, inode_usage, inode_total: Same values as block, but 
     for inodes
 * Process:
   * total_memory: Memory usage of process and all children proces
   * total_cpu: CPU usage of process and all children process
   * response_time: monit supports checking a service within a process
     checking, and adds response time if it's available (or nil if not)

I added tests for these values too, and fixed formatting of source where
it is needed. All tests are passing