Cleanup check_sources and remove hard tabs from some files.

Improved and documented the check_sources script, and after running it, used
untabify to cleanup the files  where it reported hard tabs.

tools/check_sources.py

@@ -1,18 +1,32 b''
 #!/usr/bin/env python
 """Utility to look for hard tabs and \r characters in all sources.
+
+Usage:
+
+./check_sources.py
+
+It prints summaries and if chosen, line-by-line info of where \\t or \\r
+characters can be found in our source tree.
 """
 
-from IPython.external.path import path
+# Config
+# If true, all lines that have tabs are printed, with line number
+full_report_tabs = True
+# If true, all lines that have tabs are printed, with line number
+full_report_rets = False
 
-fs = path('..').walkfiles('*.py')
+# Code begins
+from IPython.external.path import path
 
 rets = []
+tabs = []
 
-for f in fs:
+for f in path('..').walkfiles('*.py'):
     errs = ''
     cont = f.bytes()
     if '\t' in cont:
         errs+='t'
+        tabs.append(f)
 
     if '\r' in cont:
         errs+='r'
@@ -20,13 +34,21 b' for f in fs:'
         
     if errs:
         print "%3s" % errs, f
-        if 't' in errs:
+
+    if 't' in errs and full_report_tabs:
             for ln,line in enumerate(f.lines()):
                 if '\t' in line:
                     print 'TAB:',ln,':',line,
-        if 'r' in errs:
+
+    if 'r' in errs and full_report_rets:
             for ln,line in enumerate(open(f.abspath(),'rb')):
                 if '\r' in line:
                     print 'RET:',ln,':',line,
 
-rr = rets[-1]
+# Summary at the end, to call cleanup tools if necessary
+if tabs:
+    print 'Hard tabs found. These can be cleaned with untabify:'
+    for f in tabs: print f,
+if rets:
+    print 'Carriage returns (\\r) found in:'
+    for f in rets: print f,