Table name is in form of full file path on Windows

[vovcacik]

Hi, textql is creating a table for each input file using the base filename without extension. However this is not the case on Windows where the table name is full path of file without extension (including colon and backslashes).

textql version: commit 01160a69ae3b9ea1258f979093c39ed6b59c8b46 OS: Windows 10

# trunk version with the bug
C:\textql>textql -console test.txt
SQLite version 3.22.0 2018-01-22 18:45:57
Enter ".help" for usage hints.
sqlite> .tables
C:\textql\test
sqlite> .quit

# trunk version with bugfix
C:\textql>textql -console test.txt
SQLite version 3.22.0 2018-01-22 18:45:57
Enter ".help" for usage hints.
sqlite> .tables
test
sqlite> .quit