change m_map high to intermediate resolution and and high resolution

add simplifications submit by Thierry Reynaud:
  latRange = (latMax-latMin);
  latMin = max(floor(latMin), -90);
  latMax = min(ceil(latMax), 90);

  lonRange = (lonMax-lonMin);
  lonMin = floor(lonMin);
  lonMax = ceil(lonMax);

tsg_util/plot_map.m

@@ -51,12 +51,12 @@ if ~isempty( ind )
   % Oversize window due to the large frame
   %--------------------------------------
   latRange = (latMax-latMin);
-  latMin = max(min(latMin - 0.05*latRange, latMin - 2), -90);
-  latMax = min(max(latMax + 0.05*latRange, latMax + 2), 90);
+  latMin = max(floor(latMin), -90);
+  latMax = min(ceil(latMax), 90);
 
   lonRange = (lonMax-lonMin);
-  lonMin = min(lonMin - 0.03*lonRange, lonMin -2);
-  lonMax = max(lonMax + 0.03*lonRange, lonMax +2);
+  lonMin = floor(lonMin);
+  lonMax = ceil(lonMax);
 
   lonRange = (lonMax-lonMin);
   if lonRange>=360
@@ -90,10 +90,15 @@ if ~isempty( ind )
       m_gshhs_l('patch',[.7 .7 .7], 'TAG', 'TAG_PLOT4_LINE_COAST');
 
     case 3
-      % High-resolution coast lines
+      % Intermediate-resolution coast lines
       % ----------------------------
       m_gshhs_i('patch',[.7 .7 .7], 'TAG', 'TAG_PLOT4_LINE_COAST');
-
+      
+    case 4
+      % High-resolution coast lines
+      % ----------------------------
+      m_gshhs_h('patch',[.7 .7 .7], 'TAG', 'TAG_PLOT4_LINE_COAST');
+      
     otherwise
       tsg.preference.map_resolution = 1;
       % Low-resolution coast lines