Support reading from stdin

[staabm]

this change implements reading from stdin, so the command can be used in a unix-pipe style:

tools/sql-parser$ echo "SELECT 1" | php bin/highlight-query
SELECT
    1

tools/sql-parser$ echo "SELECT 1" | php bin/lint-query
tools/sql-parser$ echo $?
0

tools/sql-parser$ echo "abc" | php bin/lint-query
#1: Unexpected beginning of statement. (near "abc" at position 0)
tools/sql-parser$ echo $?
10

tools/sql-parser$ echo "SELECT 1" | php bin/tokenize-query
[TOKEN 0]
Type = 1
Flags = 3
Value = 'SELECT'
Token = 'SELECT'

[TOKEN 1]
Type = 3
Flags = 0
Value = ' '
Token = ' '

[TOKEN 2]
Type = 6
Flags = 0
Value = 1
Token = '1'

[TOKEN 3]
Type = 3
Flags = 0
Value = ' '
Token = '
'

[TOKEN 4]
Type = 9
Flags = 0
Value = NULL
Token = NULL

refs #237

[codecov]

Codecov Report

Merging #239 into master will decrease coverage by 0.07%.
The diff coverage is 78.57%.

@@             Coverage Diff              @@
##             master     #239      +/-   ##
============================================
- Coverage      99.7%   99.63%   -0.08%     
- Complexity     1842     1849       +7     
============================================
  Files            61       61              
  Lines          4104     4118      +14     
============================================
+ Hits           4092     4103      +11     
- Misses           12       15       +3