added: package ecl-summary
Merge pull request #35 from akva2/install_ecl_summary

added: package ecl-summary
Added time_interval implementation
Added time_interval_has_overlap()
Added several methods to time_interval implementation
Added time_interval_intersect() and _extend
Added code for initializing a time_t vector with monthly time_t values
Adde code to initialie date_lit with monthly values
Merge branch 'python-cleanup' into esummary
Started to base timing in ecl_sum_data on time_interval implementation
Added time_interval_equal() and time_interval_alloc_copy()
Changed ecl_sum_data to use time interval
Updated esummary to interpolate consistently
Added util_before / util_after functions
Merge branch 'esummary'
Bug in test
Added vector_inplace_reverse to reverse a vector
Added stringlist_reverse to reverse a stringlist
Changed well_ts_add_well() to append + sort, instead of moving around in the vector
Force wellhead to k => 0 if k >= nz