Fix build when glib is in non-standard location (e.g. /opt).
Use the "C" locale when parsing data returned by the caching daemon.
Merge pull request #365 from octo/ff/locale

Use the "C" locale when parsing data returned by the caching daemon.
Merge pull request #360 from mkhon/master

Fix build with non-standard glib location
Fixed overflow bug.
Added check for graph timespan overflowing if time_t is 32 bits.
Merge pull request #369 from nhale25/master

Fixes relating to databases covering large timespans.
positional legends in AREA and LINE are optional if they are the last argument
improve rrd_graph performance for large (>1000) number of *DEF variables by using hash_table lookups instead of linear search
when using \ to escape a character from processing, the \ should not show up in the final result
only add *DEF entries to the hash_table
added sample data
only \: should be handled here other escapes are handled later on
fix parsing of HRULE and VRULE with absolute values
unified return codes for parse errors
raise an error if part of an CDEF is unparsable
LINE: should have width 1 and not width 0
fixed overflow probem with partial matching
add a gitignore file

It contains common exclusion rules, autoconf stuff, automake stuff,
cscope and po. It is expected that a user would use a `build/`
directory to build stuff.
build: allow out-of-tree build

Building out of the tree is convenient because we there it does not
pollute VCS status and make it convenient to clean everything by just
removing the build directory.

Currently, the build won't work with Perl, Python and Ruby bindings.