Changes

Fixed some oversights for the bv_efold commits and increased string length for tuning field names for invrs_tau variables - CLUBB ticket #1069 (#1106)

This commit is NOT bit changing
- Removed remaining mentions of brunt_vaisala_freq_sqd_plus
- Added assignment for invrs_tau_wp3_zm in Lscale mode in advance_clubb_core
- Increased length of string variables hoc_v, les_v, and t_variables in src/error.F90 to accomodate tuning for invrs_tau fields

BIT_CHANGING! brunt_vaisala_freq_sqd_mixed now replaces brunt_vaisala_freq_sqd for later calculations - CLUBB ticket #1102

Changes in src/CLUBB_core/mixing_length.F90:
- brunt_vaisala_freq_sqd_mixed is now used to calculate brunt_vaisala_freq_sqd_smth and brunt_vaisala_freq_sqd_clipped instead of brunt_vaisala_freq_sqd
- Removed 0.1 factor for bkgnd term in calculation of invrs_tau_xp2_zm
- Commented out clipping of invrs_tau_xp2_zm to 0.003 and lower out of cloud

BIT_CHANGING for lscale setup. Updated configurable_model_flags.in and model_flags.F90 - CLUBB ticket #1102 (#1108)

- Added new flags to inut/tunable_parameters_Lscale/configurable_model_flags.in
- Changed default setting for l_use_tke_in_wp3_pr_turb_term in model_flags.F90 from false to true

Likely BIT_CHANGING because of added output fields. Added code outputting C6_term and different Brunt Vaisala frequencies to disk - CLUBB ticket #1102 (#1109)

- Added C6_term and bv_freq fields to all_stats.F90 and standard_stats.F90
- Added new fields to VariableGroupTaus.py in pyplotgen
- Added calls to stat_update_var to advance_clubb_core_module.F90
- Modified stats_variables.F90 and stats_zm_module.F90 accordingly

Changed sqrt_Ri_zm to Ri_zm in preparation of changing the exponent for calculation of invrs_tau_wpxp_zm in mixing_length.F90 - CLUBB ticket #1102 (#1110)

BIT_CHANGING! Changed sqrt_Ri_zm to Ri_zm in preparation of changing the exponent for calculation of invrs_tau_wpxp_zm in mixing_length.F90 - CLUBB ticket #1102
Changes in input/stats/all_stats.in, src/CLUBB_core/advance_clubb_core_module.F90, src/CLUBB_core/mixing_length.F90, src/CLUBB_core/stats_variables.F90, and src/CLUBB_core/stats_zm_module.F90
Ri_zm was added to input/stats/standard_stats.in

BIT_CHANGING! Removed Richardson_num and all corresponding code - CLUBB ticket #1102 (#1111)

This commit is BIT_CHANGING because:
1. the output field Richardson_num was removed.
2. Since the flag l_use_shear_turb_freq_sqd was removed, the variable shear_sqd is now always written to disk. That means previously, the outputted field shear_sqd was 0 everywhere whereas now it is not anymore. The calculation of shear_sqd within CLUBB did not change!
- Removed mentions in input/stats/all_stats.in and standards_stats.in
- Removed mentions in src/CLUBB_core/stats_variables.F90 and stats_zm_module.F90
- In src/CLUBB_core/advance_helper_module.F90 removed mentions to [i]Richardson_num[_clipped], as well as l_use_shear_turb_freq_sqd, l_Richardson_vert_avg, and turb_freq_sqd sinc those are only used for calculation of Richardson_num.

Tunable Richardson number exponent - CLUBB ticket #1102 (#1114)

BIT_CHANGING! Added the exponent to the Richardson number in the calculation of the invrs_tau_wpxp threshold term in src/CLUBB_core/mixing_length.F90  to the list of tunable parameters.
This is bit changing due to the difference in Fortran between taking the sqrt and the .5th power.

Tunable Richardson number exponent - CLUBB ticket #1102 (#1114)

BIT_CHANGING! Added the exponent to the Richardson number in the calculation of the invrs_tau_wpxp threshold term in src/CLUBB_core/mixing_length.F90  to the list of tunable parameters.
This is bit changing due to the difference in Fortran between taking the sqrt and the .5th power.

Deletes svn id tag, will trigger host-model nightly tests.

Remove svn id tag in order to trigger nightly tests.

Removed 3rd svn id tag in order to trigger nightly tests