dbstatic: raise link field length limit to 256 by bumping internal buffer size

documentation/RELEASE_NOTES.html

@@ -14,6 +14,13 @@
 <h2 align="center">Changes between 3.15.1 and 3.15.2</h2>
 <!-- Insert new items immediately below here ... -->
 
+<h3>Raised limit on link field length in database files</h3>
+
+<p>The length of INP/OUT link fields in database files was limited to 79 chars
+by an internal buffer size in the db file parser. This limitation will go away
+completely in 3.16, and has been statically raised to 255 chars for the 3.15
+series.</p>
+
 <h3>aoRecord raw conversion overflows</h3>
 
 <p>The ao record type now checks converted raw values and limits them to the

src/ioc/dbStatic/dbStaticLib.c

@@ -2087,7 +2087,7 @@ long dbPutString(DBENTRY *pdbentry,const char *pstring)
     case DBF_OUTLINK:
     case DBF_FWDLINK: {
 	    DBLINK	*plink;
-	    char	string[80];
+        char	string[256];
 	    char	*pstr = string;
 
 	    if (!pfield)