(CFACT-88) Replace string utility functions with those in Boost.

Replacing the following string utility functions with Boost string
algorithms:

* starts_with
* ends_with
* ltrim
* rtrim
* trim
* tokenize
* split
* to_lower
* to_upper

Also removing the unused ci_string type.  Boost has functionality for
doing case insensitive comparisons.
Merge pull request #109 from peterhuene/maint/strings

(CFACT-88) Replace string utility functions with those in Boost.
(CFACT 70) Add filesystem facts for solaris

Before this patch, solaris did not provide the filesystem facts. This patch
adds support for filesystem facts for solaris. Unlike linux, there is no direct
means to find supported filesystems, and hence we use the bsd approach, and
list only the currently in use filesystems. We also leave the partitions
support unimplemented for now.